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Apply properties of integer exponents

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5245778
Rewrite each expression without a fraction bar by using negative exponents. a) \(\frac{1}{10000}\) b) \(\frac{1}{32}\) c) \(\frac{4}{x^3}\), where \(x\ne0\) d) \(\frac{y^5}{z^2}\), where \(z\ne0\)

Hints

- A factor moved from the denominator to the numerator receives a negative exponent. - Rewrite numerical denominators as powers. - Keep coefficients and numerator factors unchanged.

Solution

1. Since \(10{,}000=10^4\), \(\frac{1}{10000}=10^{-4}\). 2. Since \(32=2^5\), \(\frac{1}{32}=2^{-5}\). 3. \(\frac{4}{x^3}=4x^{-3}\). 4. \(\frac{y^5}{z^2}=y^5z^{-2}\).

Answer

a) \(10^{-4}\) b) \(2^{-5}\) c) \(4x^{-3}\) d) \(y^5z^{-2}\)
5100638
Simplify \(2x^2y \cdot 3x^3y\). a) \(6x^6y\) b) \(6x^6y^2\) c) \(6x^5y\) d) \(6x^5y^2\)

Hints

- Work with the coefficients and variables separately. - Add exponents when multiplying powers with the same base. - A variable with no written exponent has exponent \(1\).

Solution

1. Multiply the coefficients: \(2 \cdot 3 = 6\). 2. Add exponents for the same base: \(x^2 \cdot x^3 = x^{2+3} = x^5\). 3. Since each factor contains \(y^1\), \(y \cdot y = y^{1+1} = y^2\). 4. The product is \(6x^5y^2\).

Answer

d) \(6x^5y^2\)
5103948
Simplify each expression. a) \(\frac{(-3)^2}{-9}\) b) \(\frac{-3^2}{-9}\) c) \(-\frac{-3^2}{9}\)

Hints

- Determine whether the negative sign is included in the base being squared. - A quotient of two negative numbers is positive. - The product of two negative values is positive.

Solution

1. a) The parentheses make the negative part of the base: \((-3)^2 = 9\), so \(\frac{9}{-9} = -1\). 2. b) The exponent applies only to \(3\): \(-3^2 = -(3^2) = -9\), so \(\frac{-9}{-9} = 1\). 3. c) Inside the fraction, \(-3^2 = -9\). Therefore, \(-\frac{-9}{9} = -(-1) = 1\).

Answer

a) \(-1\) b) \(1\) c) \(1\)
5103958
Let \(x = -\frac{(-1)^{101}}{5}\). Is \(x\) to the left or right of \(0\) on a number line? Explain.

Hints

- First determine the sign of the power in the numerator. Does an odd or even exponent matter? - Consider what the negative sign in front of the fraction does. - Recall where positive and negative numbers lie relative to \(0\).

Solution

1. Since \(101\) is odd, \((-1)^{101} = -1\). 2. Substitute: \(x = -\frac{-1}{5} = \frac{1}{5}\). 3. Because \(\frac{1}{5} > 0\), the point is to the right of \(0\).

Answer

The value is to the right of \(0\) because \(x = \frac{1}{5}\), which is positive.
5122298
A pattern of products grows by adding one factor of \(-3\) in each row. Row 1: \((-3)\) Row 2: \((-3) \cdot (-3)\) Row 3: \((-3) \cdot (-3) \cdot (-3)\) a) Determine the sign of the product in Row 8 without calculating its value. Explain. b) Calculate the value of the product in Row 4.

Hints

- What sign results when two negative numbers are multiplied? - How does an even or odd number of negative factors affect the sign? - You can write each row as a power.

Solution

1. Row 8 contains eight negative factors. Because eight is even, the product is positive. 2. Row 4 is \((-3)^4\). Pairing the factors gives \(9 \cdot 9 = 81\).

Answer

a) Positive, because the product has an even number of negative factors. b) \(81\)
5122328
Evaluate each expression. For parts a)–d), first write the power as repeated multiplication. a) \((-3)^4\) b) \(-3^4\) c) \((-10)^3\) d) \(-10^3\) e) \((-1)^{100}\) Briefly explain why the notation in a) and b) has different meanings.

Hints

- Determine exactly what the exponent applies to. Is the negative sign inside parentheses? - Consider how multiplying an even or odd number of negative factors affects the sign. - Follow the order of operations when a negative sign is outside a power.

Solution

1. a) \((-3)^4 = (-3) \cdot (-3) \cdot (-3) \cdot (-3) = 81\). 2. b) \(-3^4 = -(3 \cdot 3 \cdot 3 \cdot 3) = -81\). 3. c) \((-10)^3 = (-10) \cdot (-10) \cdot (-10) = -1000\). 4. d) \(-10^3 = -(10 \cdot 10 \cdot 10) = -1000\). 5. e) Since \(100\) is even, \((-1)^{100} = 1\). 6. In a), the parentheses make \(-3\) the base. In b), the exponent applies only to \(3\), and the negative sign is applied afterward.

Answer

a) \(81\) b) \(-81\) c) \(-1000\) d) \(-1000\) e) \(1\) In a), the base is \(-3\). In b), the base is \(3\), and the negative sign is outside the power.
5126768
Order the quantities from least to greatest. (1) \(10^4\) (2) \(1000\) (3) \(10^2 \cdot 10^3\) (4) \(100{,}000\) (5) \(10^7 \div 10\)

Hints

- Rewrite each quantity as a power with base \(10\). - When multiplying or dividing powers with the same base, what happens to the exponents? - Count the zeros in \(100{,}000\).

Solution

1. Rewrite each quantity as a power of \(10\): (1) \(10^4\), (2) \(10^3\), (3) \(10^{2+3} = 10^5\), (4) \(10^5\), and (5) \(10^{7-1} = 10^6\). 2. Compare the exponents: \(3 < 4 < 5 < 6\). 3. Therefore, \(1000 < 10^4 < 10^2 \cdot 10^3 = 100{,}000 < 10^7 \div 10\).

Answer

\(1000 < 10^4 < 10^2 \cdot 10^3 = 100{,}000 < 10^7 \div 10\)
5130548
Simplify each expression. Assume \(x\ne0\), \(y\ne0\), and \(z\ne0\). a) \((x^3)^4\cdot x^{-5}\) b) \(\frac{24y^6}{3y^2}\) c) \((-3a)^2\cdot a^3\) d) \(\frac{z^0\cdot z^7}{z^3}\)

Hints

- Multiply like bases by adding exponents and divide them by subtracting exponents. - For a power of a power, multiply the exponents. - A nonzero base raised to the zero power equals \(1\). - Apply an exponent to every factor inside parentheses.

Solution

1. \((x^3)^4=x^{12}\), so \(x^{12}\cdot x^{-5}=x^7\). 2. Divide the coefficients and subtract exponents: \(\frac{24y^6}{3y^2}=8y^4\). 3. \((-3a)^2=9a^2\), so \(9a^2\cdot a^3=9a^5\). 4. Since \(z^0=1\), \(\frac{z^0\cdot z^7}{z^3}=z^{7-3}=z^4\).

Answer

a) \(x^7\) b) \(8y^4\) c) \(9a^5\) d) \(z^4\)
5131088
Insert \(<\), \(>\), or \(=\) in each blank. Briefly justify your choice using exponent properties. a) \((-1)^{10}\ \_\_\_\ (-1)^{11}\) b) \(-4^2\ \_\_\_\ (-4)^2\) c) \(3^{-2}\ \_\_\_\ (-3)^{-2}\)

Hints

- Check whether the exponent is even or odd. - Notice whether a negative sign is inside or outside parentheses. - A negative exponent creates a reciprocal; it does not make the value negative.

Solution

1. \((-1)^{10}=1\) because the exponent is even, while \((-1)^{11}=-1\). Therefore, \(1>-1\). 2. The expression \(-4^2\) means \(-(4^2)=-16\), while \((-4)^2=16\). Therefore, \(-16<16\). 3. \(3^{-2}=\frac{1}{9}\), and \((-3)^{-2}=\frac{1}{(-3)^2}=\frac{1}{9}\). Therefore, the expressions are equal.

Answer

a) \(>\) b) \(<\) c) \(=\)
5134058
Simplify each expression and write the result without negative exponents. a) \(4^5\cdot4^{-7}\) b) \(\frac{3^{-2}}{3^2}\) c) \((2^{-3})^{-2}\) d) \(10^{-3}\cdot10^5\cdot10^{-2}\) e) \(\left(\frac{2}{5}\right)^{-2}\)

Hints

- Add exponents when multiplying powers with the same base. - Subtract exponents when dividing powers with the same base. - A negative exponent indicates a reciprocal.

Solution

1. For a), add exponents: \(4^{5+(-7)}=4^{-2}=\frac{1}{16}\). 2. For b), subtract exponents: \(3^{-2-2}=3^{-4}=\frac{1}{81}\). 3. For c), multiply exponents: \(2^{(-3)\cdot(-2)}=2^6=64\). 4. For d), add exponents: \(10^{-3+5-2}=10^0=1\). 5. For e), take the reciprocal and use a positive exponent: \(\left(\frac{5}{2}\right)^2=\frac{25}{4}=6.25\).

Answer

a) \(\frac{1}{16}\) b) \(\frac{1}{81}\) c) \(64\) d) \(1\) e) \(\frac{25}{4}\)
5134088
Paul claims that for \(a\ne0\), \(\frac{a^3}{a^5}\) is equal to \(a^{-2}\). a) Expand the powers as repeated factors and simplify by canceling. b) Explain how your result from part a) relates to \(a^{-2}\). c) State a general rule for \(\frac{a^m}{a^n}\) that also applies when \(n>m\).

Hints

- Write each power as repeated multiplication. - Cancel matching factors in the numerator and denominator. - Recall the definition of a negative exponent.

Solution

1. Expand and cancel: \(\frac{a\cdot a\cdot a}{a\cdot a\cdot a\cdot a\cdot a}=\frac{1}{a^2}\). 2. By the definition of a negative exponent, \(a^{-2}=\frac{1}{a^2}\), so Paul’s claim is true. 3. For \(a\ne0\), the quotient rule is \(\frac{a^m}{a^n}=a^{m-n}\). When \(n>m\), the exponent \(m-n\) is negative.

Answer

a) \(\frac{1}{a^2}\) b) \(\frac{1}{a^2}=a^{-2}\), so the claim is true. c) For \(a\ne0\), \(\frac{a^m}{a^n}=a^{m-n}\).
5134148
Which expressions are equivalent to \(x^7\) for \(x\ne0\)? Select all that apply. A. \(x^3\cdot x^4\) B. \(\frac{x^{10}}{x^3}\) C. \((x^{-1})^{-7}\) D. \(x^7+x^7\) E. \(\frac{1}{x^{-7}}\) F. \(x^{14}\div x^2\) G. \(x^7\cdot x^0\)

Hints

- Apply the product, quotient, and power-of-a-power rules. - Distinguish addition of like terms from multiplication of powers. - Recall that \(x^0=1\) for \(x\ne0\).

Solution

1. \(A=x^{3+4}=x^7\). 2. \(B=x^{10-3}=x^7\). 3. \(C=x^{(-1)\cdot(-7)}=x^7\). 4. \(D=2x^7\), so it is not equivalent. 5. \(E=x^7\). 6. \(F=x^{14-2}=x^{12}\), so it is not equivalent. 7. Since \(x^0=1\), \(G=x^7\).

Answer

A, B, C, E, and G
5134178
Assume all variables are nonzero. Simplify each expression and write the result without negative exponents. a) \(a^{-4}\cdot a^7\) b) \(b^2\div b^6\) c) \((c^{-2})^{-4}\) d) \(\frac{15x^3}{5x^8}\) e) \(\left(\frac{1}{y^3}\right)^{-2}\)

Hints

- Add exponents when multiplying powers with the same base. - Subtract exponents when dividing. - Rewrite negative exponents as reciprocals at the end.

Solution

1. For a), \(a^{-4+7}=a^3\). 2. For b), \(b^{2-6}=b^{-4}=\frac{1}{b^4}\). 3. For c), \(c^{(-2)\cdot(-4)}=c^8\). 4. For d), \(\frac{15}{5}x^{3-8}=3x^{-5}=\frac{3}{x^5}\). 5. For e), \((y^{-3})^{-2}=y^6\).

Answer

a) \(a^3\) b) \(\frac{1}{b^4}\) c) \(c^8\) d) \(\frac{3}{x^5}\) e) \(y^6\)
5134238
Assume \(a\ne0\) and \(b\ne0\). Decide whether each statement is true or false. Correct each false statement. a) \(a^{-4}\cdot a^4=0\) b) \(\frac{b^2}{b^{-3}}=b^5\) c) \((2^{-1})^3=\frac{1}{8}\)

Hints

- Add exponents when multiplying powers with the same base. - Subtract the denominator exponent when dividing. - Recall that a nonzero number to the zero power equals \(1\).

Solution

1. For a), \(a^{-4}a^4=a^0=1\), so the statement is false. 2. For b), \(\frac{b^2}{b^{-3}}=b^{2-(-3)}=b^5\), so the statement is true. 3. For c), \((2^{-1})^3=2^{-3}=\frac{1}{8}\), so the statement is true.

Answer

a) False. The correct equation is \(a^{-4}\cdot a^4=1\). b) True. c) True.
5134268
Evaluate without a calculator by applying exponent properties. a) \(3^5\cdot3^{-7}\) b) \(\left(\frac{1}{2}\right)^{-3}\cdot2^{-2}\) c) \(10^{-4}\div10^{-6}\) d) \((-5)^3\cdot(-5)^{-3}\)

Hints

- Add exponents when multiplying powers with the same base. - Subtract exponents when dividing. - A negative exponent on a fraction reverses the fraction.

Solution

1. For a), \(3^{5+(-7)}=3^{-2}=\frac{1}{9}\). 2. For b), \(\left(\frac{1}{2}\right)^{-3}=2^3\), so \(2^3\cdot2^{-2}=2\). 3. For c), \(10^{-4-(-6)}=10^2=100\). 4. For d), \((-5)^{3+(-3)}=(-5)^0=1\).

Answer

a) \(\frac{1}{9}\) b) \(2\) c) \(100\) d) \(1\)
5134308
Simplify each expression and write the result as a single power of \(10\). a) \(\frac{1}{100000}\) b) \(0.001\cdot10^{-4}\) c) \(\frac{10^{-2}}{10^5}\) d) \((10^{-3})^2\cdot10^4\)

Hints

- Rewrite decimal powers of ten using exponents. - Add exponents when multiplying and subtract them when dividing. - Multiply exponents when raising a power to a power.

Solution

1. For a), \(100{,}000=10^5\), so \(\frac{1}{100000}=10^{-5}\). 2. For b), \(0.001=10^{-3}\), so \(10^{-3}\cdot10^{-4}=10^{-7}\). 3. For c), \(10^{-2}\div10^5=10^{-2-5}=10^{-7}\). 4. For d), \((10^{-3})^2\cdot10^4=10^{-6+4}=10^{-2}\).

Answer

a) \(10^{-5}\) b) \(10^{-7}\) c) \(10^{-7}\) d) \(10^{-2}\)
5134328
Assume all variables are nonzero. Simplify using exponent properties and write each result without negative exponents. a) \(a^5\cdot a^{-9}\) b) \(x^{-3}\div x^{-5}\) c) \((y^{-2})^4\) d) \(b^2\cdot b^{-2}\)

Hints

- Add exponents when multiplying and subtract them when dividing. - Multiply exponents when raising a power to a power. - Rewrite negative exponents as reciprocals.

Solution

1. For a), \(a^{5+(-9)}=a^{-4}=\frac{1}{a^4}\). 2. For b), \(x^{-3-(-5)}=x^2\). 3. For c), \(y^{(-2)\cdot4}=y^{-8}=\frac{1}{y^8}\). 4. For d), \(b^{2+(-2)}=b^0=1\).

Answer

a) \(\frac{1}{a^4}\) b) \(x^2\) c) \(\frac{1}{y^8}\) d) \(1\)
5134358
Maria made an error in each solution. Describe each error and give the correct result. Assume \(x\ne0\) and \(a\ne0\). a) \(3^{-2}=-9\) b) \(\frac{1}{x^5}=x^5\) c) \(2a^{-3}=\frac{1}{2a^3}\)

Hints

- A negative exponent creates a reciprocal. - Moving a factor across a fraction bar changes the exponent’s sign. - An exponent applies only to the base immediately before it unless parentheses show otherwise.

Solution

1. In a), a negative exponent means a reciprocal, not a negative value: \(3^{-2}=\frac{1}{3^2}=\frac{1}{9}\). 2. In b), moving a power across the fraction bar changes the sign of the exponent: \(\frac{1}{x^5}=x^{-5}\). 3. In c), the exponent applies only to \(a\), not to the coefficient \(2\): \(2a^{-3}=\frac{2}{a^3}\).

Answer

a) A negative exponent means a reciprocal, not a negative value: \(3^{-2}=\frac{1}{9}\). b) Moving a power across the fraction bar changes the exponent sign: \(\frac{1}{x^5}=x^{-5}\). c) The exponent applies only to \(a\), not to \(2\): \(2a^{-3}=\frac{2}{a^3}\).
5134378
For any nonzero base \(a\) and integer exponent \(n\), determine whether each statement is true or false. Justify your decision by simplifying the left side. a) \(a^n a^{-n}=1\) b) \((a^{-1})^n=\frac{1}{a^n}\) c) \(\frac{a^n}{a^{n+2}}=a^2\)

Hints

- Apply the product, quotient, and power-of-a-power rules. - A nonzero base raised to the zero power equals \(1\). - Distribute a subtraction sign across grouped terms in an exponent.

Solution

1. For a), \(a^n a^{-n}=a^{n-n}=a^0=1\), so the statement is true. 2. For b), \((a^{-1})^n=a^{-n}=\frac{1}{a^n}\), so the statement is true. 3. For c), \(\frac{a^n}{a^{n+2}}=a^{n-(n+2)}=a^{-2}=\frac{1}{a^2}\), so the statement is false.

Answer

a) True. b) True. c) False; the left side equals \(\frac{1}{a^2}\).
5134448
Assume all variables are nonzero. Simplify and write each result without negative exponents. a) \(a^5a^{-8}a^4\) b) \((-x)^2x^{-5}\) c) \(\frac{b^2}{b^{-3}}\)

Hints

- Add exponents when multiplying powers with the same base. - Square the negative base before combining powers. - Subtracting a negative exponent is addition.

Solution

1. For a), \(a^{5-8+4}=a\). 2. For b), \((-x)^2=x^2\), so \(x^2x^{-5}=x^{-3}=\frac{1}{x^3}\). 3. For c), \(b^{2-(-3)}=b^5\).

Answer

a) \(a\) b) \(\frac{1}{x^3}\) c) \(b^5\)
5134898
Simplify each expression as far as possible. a) \(\left(\frac{x}{y}\right)^4\left(\frac{y}{x}\right)^2\) b) \(\left(\frac{a}{b}\right)^2\div\frac{a^3}{b}\) c) \(\left(\frac{m}{n}\right)^{-2}\cdot\frac{m^2}{n^2}\)

Hints

- Apply powers to both numerator and denominator. - Rewrite division as multiplication by the reciprocal. - A negative exponent on a fraction reverses the fraction.

Solution

1. For a), \(\frac{x^4}{y^4}\cdot\frac{y^2}{x^2}=\frac{x^2}{y^2}\), where \(x\ne0\) and \(y\ne0\). 2. For b), \(\frac{a^2}{b^2}\cdot\frac{b}{a^3}=\frac{1}{ab}\), where \(a\ne0\) and \(b\ne0\). 3. For c), \(\left(\frac{n}{m}\right)^2\cdot\frac{m^2}{n^2}=1\), where \(m\ne0\) and \(n\ne0\).

Answer

a) \(\frac{x^2}{y^2}\), where \(x\ne0\) and \(y\ne0\) b) \(\frac{1}{ab}\), where \(a\ne0\) and \(b\ne0\) c) \(1\), where \(m\ne0\) and \(n\ne0\)
5134928
Simplify each expression and write the result without negative exponents. a) \(x^3x^{-5}\), where \(x\ne0\) b) \(\frac{a^{-2}}{a^{-4}}\), where \(a\ne0\) c) \((y-1)^2(y-1)^{-3}\), where \(y\ne1\) d) \(2z^{-3}z\), where \(z\ne0\)

Hints

- Treat a repeated binomial as a single base. - Add exponents when multiplying and subtract them when dividing. - Rewrite a negative exponent as a reciprocal.

Solution

1. For a), \(x^{3-5}=x^{-2}=\frac{1}{x^2}\). 2. For b), \(a^{-2-(-4)}=a^2\). 3. For c), \((y-1)^{2-3}=(y-1)^{-1}=\frac{1}{y-1}\). 4. For d), \(2z^{-3+1}=2z^{-2}=\frac{2}{z^2}\).

Answer

a) \(\frac{1}{x^2}\) b) \(a^2\) c) \(\frac{1}{y-1}\) d) \(\frac{2}{z^2}\)
5139278
Evaluate or simplify without a calculator. Assume \(x\ne0\) in part b. a) \((-5)^2\) and \(-5^2\) b) \(\frac{x^6}{x^2\cdot x^3}\) c) \((2a^3)^4\) d) \(10^3\cdot10^{-5}\)

Hints

- Determine whether the negative sign is part of the base. - Add exponents when multiplying like bases and subtract them when dividing. - Multiply exponents for a power of a power. - Rewrite a negative exponent as a reciprocal.

Solution

1. \((-5)^2=25\), while \(-5^2=-(5^2)=-25\). 2. The denominator is \(x^2\cdot x^3=x^5\), so \(\frac{x^6}{x^5}=x\). 3. \((2a^3)^4=2^4(a^3)^4=16a^{12}\). 4. \(10^3\cdot10^{-5}=10^{-2}=\frac{1}{100}=0.01\).

Answer

a) \(25\) and \(-25\) b) \(x\) c) \(16a^{12}\) d) \(0.01\)
5139548
Determine whether each statement is true. Correct every false statement. a) \((5z)^2 = 25z^2\) b) \((-x)^2 = -x^2\) c) \(a^4 \cdot a^2 = a^8\) d) \((2k)^3 = 8k^3\) e) The variables \(M\) and \(m\) always represent the same value in a formula.

Hints

- An exponent outside parentheses applies to every factor inside. - Add exponents when multiplying powers with the same base. - Distinguish a negative sign inside the base from one outside a power. - Mathematical notation is case-sensitive.

Solution

1. a) True: \((5z)^2 = 5^2z^2 = 25z^2\). 2. b) False: \((-x)^2 = (-x)(-x) = x^2\). 3. c) False: powers with the same base are multiplied by adding exponents, so \(a^4 \cdot a^2 = a^6\). 4. d) True: \((2k)^3 = 2^3k^3 = 8k^3\). 5. e) False: uppercase and lowercase letters name different variables, so \(M\) and \(m\) need not have the same value.

Answer

a) True b) False; \((-x)^2 = x^2\) c) False; \(a^4 \cdot a^2 = a^6\) d) True e) False; \(M\) and \(m\) are different variables.
5140448
Three of these expressions are equivalent for \(x\ne0\), and one is not. Identify the expression that is not equivalent and justify your choice. A. \(\frac{4}{x^2}\) B. \(4x^{-2}\) C. \((2x)^{-2}\cdot16\) D. \(4\cdot\frac{1}{x^{-2}}\)

Hints

- Rewrite every negative exponent as a reciprocal. - Apply the exponent to the coefficient inside parentheses. - Put all four expressions in the same form before comparing.

Solution

1. \(A=\frac{4}{x^2}\). 2. \(B=4x^{-2}=\frac{4}{x^2}\). 3. \(C=(2x)^{-2}\cdot16=\frac{16}{(2x)^2}=\frac{4}{x^2}\). 4. \(D=4\cdot\frac{1}{x^{-2}}=4x^2\), so it is not equivalent to the others for all nonzero \(x\).

Answer

D is not equivalent. A, B, and C simplify to \(\frac{4}{x^2}\), while D simplifies to \(4x^2\).
5141578
Find all rational numbers \(a\) that satisfy \(25a^{-2}=4\).

Hints

- Rewrite the negative exponent as a reciprocal. - Isolate \(a^2\). - Remember both square roots of a positive number.

Solution

1. Rewrite the negative exponent: \(25a^{-2}=\frac{25}{a^2}\). 2. Solve \(\frac{25}{a^2}=4\): \(25=4a^2\), so \(a^2=\frac{25}{4}\). 3. Taking both square roots gives \(a=\pm\frac{5}{2}\).

Answer

\(a=-\frac{5}{2}\) or \(a=\frac{5}{2}\)
5141768
Assume \(y\ne0\). Simplify using exponent properties: \(y^{-5}(y^2)^3\)

Hints

- Multiply exponents when raising a power to a power. - Add exponents when multiplying powers with the same base.

Solution

1. Raise the power to a power: \((y^2)^3=y^6\). 2. Multiply powers with the same base: \(y^{-5}y^6=y^{-5+6}=y\).

Answer

\(y\)
5141798
Evaluate without a calculator. Use exponent properties to simplify. a) \(3^6\cdot3^{-7}\cdot9\) b) \(10^{-2}\div10^{-5}\cdot0.1^2\)

Hints

- Rewrite \(9\) and \(0.1\) as powers with matching bases. - Add exponents when multiplying and subtract when dividing. - Follow multiplication and division from left to right.

Solution

1. For a), write \(9=3^2\): \(3^{6-7+2}=3\). 2. For b), \(10^{-2}\div10^{-5}=10^3\), and \(0.1^2=(10^{-1})^2=10^{-2}\). 3. Therefore, \(10^3\cdot10^{-2}=10\).

Answer

a) \(3\) b) \(10\)
5149388
Simplify and write each answer without negative exponents. Assume \(x\ne0\), \(y\ne0\), \(z\ne0\), and \(a\ne0\). a) \(x^4\cdot x^{-6}\) b) \(\frac{y^{-2}}{y^3}\) c) \((-2z)^{-3}\) d) \((a^2\cdot a^{-3})^2\)

Hints

- Add exponents when multiplying like bases and subtract them when dividing. - Rewrite a negative exponent as a reciprocal. - Simplify inside parentheses before applying an outside exponent.

Solution

1. \(x^4\cdot x^{-6}=x^{-2}=\frac{1}{x^2}\). 2. \(\frac{y^{-2}}{y^3}=y^{-5}=\frac{1}{y^5}\). 3. \((-2z)^{-3}=\frac{1}{(-2z)^3}=-\frac{1}{8z^3}\). 4. \((a^2\cdot a^{-3})^2=(a^{-1})^2=a^{-2}=\frac{1}{a^2}\).

Answer

a) \(\frac{1}{x^2}\) b) \(\frac{1}{y^5}\) c) \(-\frac{1}{8z^3}\) d) \(\frac{1}{a^2}\)
5223778
Rewrite each product using exponents. 1) \(8 \cdot 8 \cdot 8 \cdot 8 \cdot 8 \cdot 8\) 2) \(z \cdot z \cdot z \cdot z\) 3) \(3 \cdot 3 \cdot 3 \cdot a \cdot a \cdot b \cdot b \cdot b \cdot b\) 4) Which expression can be written as \(x^4\): \(x + x + x + x\) or \(x \cdot x \cdot x \cdot x\)? Briefly explain.

Hints

- An exponent tells how many times the base is used as a factor. - Distinguish repeated addition from repeated multiplication. - Group equal factors before writing powers.

Solution

1. Six equal factors of \(8\) give \(8^6\). 2. Four equal factors of \(z\) give \(z^4\). 3. Group equal factors: \(3^3a^2b^4\). 4. \(x^4\) represents repeated multiplication, so \(x \cdot x \cdot x \cdot x = x^4\). The sum \(x + x + x + x\) equals \(4x\).

Answer

1) \(8^6\) 2) \(z^4\) 3) \(3^3a^2b^4\) 4) \(x \cdot x \cdot x \cdot x\), because exponents represent repeated multiplication.
5223788
Rewrite each expression as concisely as possible using exponents. 1) A product of nine factors of \(c\) 2) \(4 \cdot 4 \cdot r \cdot r \cdot r + s \cdot s \cdot s \cdot s \cdot s\) 3) \(x \cdot x \cdot y \cdot y \cdot y \cdot x \cdot y\) 4) The product \(p \cdot p \cdot \ldots \cdot p\) contains \(n\) factors. Write it using exponent notation.

Hints

- Rearrange factors so equal variables are next to each other. - A plus sign separates terms; do not combine factors across it. - Use the definition of a power with \(n\) equal factors.

Solution

1. Nine factors of \(c\) give \(c^9\). 2. Group equal factors in each term: \(4^2r^3 + s^5\). 3. There are three factors of \(x\) and four factors of \(y\), so the product is \(x^3y^4\). 4. A product of \(n\) factors of \(p\) is \(p^n\).

Answer

1) \(c^9\) 2) \(4^2r^3 + s^5\) 3) \(x^3y^4\) 4) \(p^n\)
5223798
Convert each expression to the other form. Expand powers as products, and rewrite products using exponents. 1) \(6^3\) 2) \(b \cdot b \cdot b \cdot b\) 3) \(3 \cdot x \cdot x \cdot y \cdot y \cdot y\) 4) \((a + b)^2\) 5) \(7 \cdot m \cdot m\)

Hints

- An exponent tells how many equal factors are multiplied. - Identify the complete base of each power. - Keep coefficients separate from exponents on variables.

Solution

1. \(6^3 = 6 \cdot 6 \cdot 6\). 2. Four factors of \(b\) give \(b^4\). 3. Two factors of \(x\) and three factors of \(y\) give \(3x^2y^3\). 4. The entire binomial is the base: \((a + b)^2 = (a + b)(a + b)\). 5. Two factors of \(m\) give \(7m^2\).

Answer

1) \(6 \cdot 6 \cdot 6\) 2) \(b^4\) 3) \(3x^2y^3\) 4) \((a + b)(a + b)\) 5) \(7m^2\)
5223918
Write each expression as concisely as possible. Use coefficients for repeated addition and exponents for repeated multiplication. 1) \(x \cdot x \cdot x + x \cdot x \cdot x\) 2) \(a \cdot a \cdot b \cdot b \cdot b + a \cdot a \cdot b \cdot b \cdot b + a \cdot a \cdot b \cdot b \cdot b\) 3) \((m + n)(m + n) + (m + n)(m + n) + (m + n)(m + n) + (m + n)(m + n)\)

Hints

- First rewrite one repeated product using exponents. - Then count how many times that identical term is added. - Keep an entire binomial together when it is the repeated factor.

Solution

1. Each repeated product is \(x^3\), and it appears twice, so the expression is \(2x^3\). 2. Each repeated product is \(a^2b^3\), and it appears three times, so the expression is \(3a^2b^3\). 3. Each repeated product is \((m + n)^2\), and it appears four times, so the expression is \(4(m + n)^2\).

Answer

1) \(2x^3\) 2) \(3a^2b^3\) 3) \(4(m + n)^2\)
5226928
Evaluate each expression. Pay close attention to parentheses and negative signs. 1) \(-4^2\) 2) \((-4)^2\) 3) \((-1)^{50}\) 4) \(\left(-\frac{1}{2}\right)^4\) 5) \(-(-2)^3\)

Hints

- Determine whether the negative sign is part of the base. - Compare \(-a^n\) with \((-a)^n\). - Evaluate a power before applying a negative sign outside it.

Solution

1. \(-4^2 = -(4^2) = -16\). 2. \((-4)^2 = 16\). 3. Since \(50\) is even, \((-1)^{50} = 1\). 4. \(\left(-\frac{1}{2}\right)^4 = \frac{1}{16}\). 5. First, \((-2)^3 = -8\). Then \(-(-8) = 8\).

Answer

1) \(-16\) 2) \(16\) 3) \(1\) 4) \(\frac{1}{16}\) 5) \(8\)
5230098
Let \(x\) and \(y\) be nonzero rational numbers. Classify each expression as always positive, always negative, or able to equal zero. a) \(x^2 + y^2\) b) \(-(x^2 + 3)\) c) \((x - y)^2\) d) \(x^4 + 10\) e) \(-x^2 - y^2\)

Hints

- Squares are never negative. - A negative sign outside a positive expression reverses its sign. - Determine whether the quantity being squared can equal \(0\).

Solution

1. a) Since \(x\) and \(y\) are nonzero, both squares are positive, so their sum is always positive. 2. b) Since \(x^2 + 3 \ge 3\), its opposite is always negative. 3. c) A square is nonnegative, and it equals \(0\) when \(x = y\), which is allowed. 4. d) Since \(x^4 \ge 0\), \(x^4 + 10\) is always positive. 5. e) Since \(x^2 + y^2 > 0\), its opposite is always negative.

Answer

a) Always positive b) Always negative c) Can equal zero when \(x = y\) d) Always positive e) Always negative
5230298
Simplify each product. a) \(x^4 \cdot x^5\) b) \((-a^3) \cdot a^2\) c) \(y \cdot y^4 \cdot y^2\) d) \((-m^2)(-m^6)\) e) \(b^n \cdot b^3\)

Hints

- Add exponents when multiplying powers with the same base. - A variable without a written exponent has exponent \(1\). - Apply the sign rules separately from the exponent rule.

Solution

1. Add exponents when multiplying powers with the same base. 2. a) \(x^{4+5} = x^9\). 3. b) \(-a^{3+2} = -a^5\). 4. c) \(y^{1+4+2} = y^7\). 5. d) The negative signs multiply to a positive sign, giving \(m^{2+6} = m^8\). 6. e) \(b^{n+3}\).

Answer

a) \(x^9\) b) \(-a^5\) c) \(y^7\) d) \(m^8\) e) \(b^{n+3}\)
5230318
Simplify each product. a) \(6x^2 \cdot 4x^5\) b) \((-3a^4)(8a^3)\) c) \(0.4y \cdot (-5y^4)\) d) \((-7b^2)(-2b^2)\) e) \(\frac{2}{5}z^6 \cdot 10z^2\)

Hints

- Multiply the coefficients separately. - Add exponents when multiplying powers with the same base. - Apply the sign rules for multiplication.

Solution

1. a) \((6 \cdot 4)x^{2+5} = 24x^7\). 2. b) \((-3 \cdot 8)a^{4+3} = -24a^7\). 3. c) \((0.4 \cdot -5)y^{1+4} = -2y^5\). 4. d) \((-7 \cdot -2)b^{2+2} = 14b^4\). 5. e) \(\left(\frac{2}{5} \cdot 10\right)z^{6+2} = 4z^8\).

Answer

a) \(24x^7\) b) \(-24a^7\) c) \(-2y^5\) d) \(14b^4\) e) \(4z^8\)
5230338
Multiply and simplify each pair of monomials. 1) \((-5a^3b)(4a^2b^4)\) 2) \((0.8x^2y^3)(-0.5xy)\) 3) \((-6m^4n^2)(-3m^2n^5)\)

Hints

- Multiply the coefficients separately. - Add exponents for each common variable base. - Apply the sign rules for multiplication.

Solution

1. \((-5 \cdot 4)a^{3+2}b^{1+4} = -20a^5b^5\). 2. \((0.8 \cdot -0.5)x^{2+1}y^{3+1} = -0.4x^3y^4\). 3. \((-6 \cdot -3)m^{4+2}n^{2+5} = 18m^6n^7\).

Answer

1) \(-20a^5b^5\) 2) \(-0.4x^3y^4\) 3) \(18m^6n^7\)
5230358
Simplify each product. a) \((7x^n)(3x^4)\) b) \((-5a^{k+2})(-2a^3)\) c) \(\left(\frac{1}{3}y^m\right)(-9y^{m-1})\)

Hints

- Multiply the coefficients. - Add exponents on common bases. - Simplify exponent expressions after adding them.

Solution

1. a) \((7 \cdot 3)x^{n+4} = 21x^{n+4}\). 2. b) \((-5 \cdot -2)a^{(k+2)+3} = 10a^{k+5}\). 3. c) \(\left(\frac{1}{3} \cdot -9\right)y^{m+(m-1)} = -3y^{2m-1}\).

Answer

a) \(21x^{n+4}\) b) \(10a^{k+5}\) c) \(-3y^{2m-1}\)
5230398
Simplify each expression. 1) \((4a^5)^2\) 2) \((-3b^2)^3\) 3) \(\left(\frac{1}{2}x^3\right)^4\) 4) \((-y^4)^2\)

Hints

- Raise every factor inside the parentheses to the outside power. - Multiply exponents when raising a power to a power. - Use even and odd exponents to determine the sign.

Solution

1. \((4a^5)^2 = 4^2a^{5 \cdot 2} = 16a^{10}\). 2. \((-3b^2)^3 = (-3)^3b^{2 \cdot 3} = -27b^6\). 3. \(\left(\frac{1}{2}x^3\right)^4 = \frac{1}{16}x^{12}\). 4. \((-y^4)^2 = (-1)^2y^{4 \cdot 2} = y^8\).

Answer

1) \(16a^{10}\) 2) \(-27b^6\) 3) \(\frac{1}{16}x^{12}\) 4) \(y^8\)
5240898
Is \(x^2 + 1 > 0\) true for every rational number \(x\)? Explain.

Hints

- Determine the least possible value of \(x^2\). - Then add \(1\) to that lower bound.

Solution

1. For every rational number \(x\), \(x^2 \ge 0\). 2. Therefore, \(x^2 + 1 \ge 1\). 3. Since \(1 > 0\), the inequality is true for every rational \(x\).

Answer

Yes. Since \(x^2 \ge 0\), \(x^2 + 1 \ge 1 > 0\).
5245428
Simplify each expression as one power of \(10\) or as a product with a power of \(10\). a) \(10^4 \cdot 10^3\) b) \(\frac{10^7}{10^2}\) c) \(4 \times 10^5 + 5 \times 10^5\) d) \(10^2 \cdot 10^2 \cdot 10^2\)

Hints

- Add exponents when multiplying powers with the same base. - Subtract exponents when dividing powers with the same base. - Treat equal powers of \(10\) as like terms in part c).

Solution

1. a) Add exponents: \(10^{4+3} = 10^7\). 2. b) Subtract exponents: \(10^{7-2} = 10^5\). 3. c) Combine like terms: \((4 + 5) \times 10^5 = 9 \times 10^5\). 4. d) Add all exponents: \(10^{2+2+2} = 10^6\).

Answer

a) \(10^7\) b) \(10^5\) c) \(9 \times 10^5\) d) \(10^6\)
5245458
Evaluate each expression in two ways: first by evaluating inside the parentheses, and then by using a property of exponents. a) \((4 \cdot 5)^3\) b) \((2^3)^2\)

Hints

- What do you get when you evaluate the expression inside the parentheses first? - Which property simplifies a power raised to another power? - How can a power of a product be applied to each factor?

Solution

1. For a), evaluate inside the parentheses first: \(4 \cdot 5 = 20\), so \(20^3 = 8000\). 2. Using the power of a product property: \((4 \cdot 5)^3 = 4^3 \cdot 5^3 = 64 \cdot 125 = 8000\). 3. For b), evaluate the inner power first: \(2^3 = 8\), so \(8^2 = 64\). 4. Using the power of a power property: \((2^3)^2 = 2^{3 \cdot 2} = 2^6 = 64\).

Answer

a) \(8000\) b) \(64\)
5245468
Let \(A = [(-2)^2]^3\) and \(B = [(-2)^3]^2\). a) Evaluate \(A\) and \(B\) step by step, working from the inside out. b) Use a property of exponents to write both expressions as the same power with base \(-2\). Explain why this shows that the expressions are equal.

Hints

- Pay attention to whether the exponent on a negative base is even or odd. - Which property applies to a power raised to another power? - Does changing the order of the two exponent factors change their product?

Solution

1. Evaluate \(A\): \((-2)^2 = 4\), and then \(4^3 = 64\). 2. Evaluate \(B\): \((-2)^3 = -8\), and then \((-8)^2 = 64\). 3. Apply the power of a power property, \((a^m)^n = a^{mn}\). 4. \(A = (-2)^{2 \cdot 3} = (-2)^6\). 5. \(B = (-2)^{3 \cdot 2} = (-2)^6\). 6. Both expressions simplify to the same power, so they are equal.

Answer

a) \(A = 64\); \(B = 64\) b) \(A = (-2)^{2 \cdot 3} = (-2)^6\) and \(B = (-2)^{3 \cdot 2} = (-2)^6\). Therefore, \(A = B\).
5245638
Evaluate each expression. Give each answer as an integer or a fraction in lowest terms. a) \(6^{-2}\) b) \(\left(\frac{2}{3}\right)^{-3}\) c) \((-0.2)^{-2}\) d) \(-4^{-2}\) e) \(24\cdot2^{-4}\)

Hints

- A negative exponent means take the reciprocal. - Notice whether a negative sign belongs to the base or stands outside the power. - Rewrite decimals as fractions when useful.

Solution

1. \(6^{-2}=\frac{1}{6^2}=\frac{1}{36}\). 2. \(\left(\frac{2}{3}\right)^{-3}=\left(\frac{3}{2}\right)^3=\frac{27}{8}\). 3. \((-0.2)^{-2}=\left(-\frac{1}{5}\right)^{-2}=(-5)^2=25\). 4. In \(-4^{-2}\), the negative sign is outside the power, so the value is \(-\frac{1}{16}\). 5. \(24\cdot2^{-4}=24\cdot\frac{1}{16}=\frac{3}{2}\).

Answer

a) \(\frac{1}{36}\) b) \(\frac{27}{8}\) c) \(25\) d) \(-\frac{1}{16}\) e) \(\frac{3}{2}\)
5245698
Evaluate using exponent properties. 1) \(2^4\cdot2^{-2}\) 2) \(\left(\frac{1}{3}\right)^{-3}\cdot3^{-2}\) 3) \(10^{-2}\cdot0.1^{-3}\)

Hints

- A reciprocal base reverses the sign of an exponent. - Add exponents when multiplying like bases. - Rewrite \(0.1\) as a power of \(10\).

Solution

1. \(2^4\cdot2^{-2}=2^{4-2}=2^2=4\). 2. \(\left(\frac{1}{3}\right)^{-3}=3^3\), so \(3^3\cdot3^{-2}=3\). 3. Since \(0.1=10^{-1}\), \(10^{-2}\cdot0.1^{-3}=10^{-2}\cdot(10^{-1})^{-3}=10^{-2}\cdot10^3=10\).

Answer

1) \(4\) 2) \(3\) 3) \(10\)
5245708
Evaluate each expression. Follow the order of operations. 1) \(\left[6-2\cdot\left(\frac{17}{5}\right)^0\right]^{-2}\) 2) \(\frac{5^{-1}\cdot25^2}{0.2^{-2}}\)

Hints

- A nonzero base raised to the zero power equals \(1\). - Follow parentheses, exponents, multiplication and division, then addition and subtraction. - Rewrite all quantities with base \(5\) when possible.

Solution

1. Since \(\left(\frac{17}{5}\right)^0=1\), the bracket equals \(6-2=4\). Thus \(4^{-2}=\frac{1}{16}=0.0625\). 2. Write all factors with base \(5\): \(25^2=5^4\) and \(0.2^{-2}=\left(\frac{1}{5}\right)^{-2}=5^2\). Therefore, \(\frac{5^{-1}\cdot5^4}{5^2}=5\).

Answer

1) \(\frac{1}{16}\), or \(0.0625\) 2) \(5\)
5245838
Rewrite each rational expression without a fraction bar by using negative exponents. 1) \(\frac{12}{x^5}\), where \(x\ne0\) 2) \(\frac{1}{(a+b)^3}\), where \(a+b\ne0\) 3) \(\frac{1}{m^2}+\frac{1}{n^2}\), where \(m\ne0\) and \(n\ne0\) 4) \(\frac{x-y}{z^2}\), where \(z\ne0\)

Hints

- Treat a parenthetical expression as a single base. - Change the sign of an exponent when moving a factor across the fraction bar. - Use parentheses around a numerator with more than one term.

Solution

1. \(\frac{12}{x^5}=12x^{-5}\). 2. \(\frac{1}{(a+b)^3}=(a+b)^{-3}\). 3. \(\frac{1}{m^2}+\frac{1}{n^2}=m^{-2}+n^{-2}\). 4. \(\frac{x-y}{z^2}=(x-y)z^{-2}\).

Answer

1) \(12x^{-5}\) 2) \((a+b)^{-3}\) 3) \(m^{-2}+n^{-2}\) 4) \((x-y)z^{-2}\)
5245898
Rewrite each rational expression as a product with no fraction bar. Use negative exponents as needed. 1) \(\frac{7x^2}{y^3}\), where \(y\ne0\) 2) \(\frac{a^4}{5b^{-2}}\), where \(b\ne0\) 3) \(\frac{u^{-1}v^2}{w^3z^{-4}}\), where \(u,w,z\ne0\) 4) \(\frac{1}{8p^2q^{-3}}\), where \(p\ne0\) and \(q\ne0\)

Hints

- Move denominator factors to the numerator by changing exponent signs. - Handle numerical coefficients separately. - A negative exponent in the denominator becomes positive in the numerator.

Solution

1. \(\frac{7x^2}{y^3}=7x^2y^{-3}\). 2. Move \(b^{-2}\) to the numerator and invert the coefficient: \(\frac{a^4}{5b^{-2}}=0.2a^4b^2\). 3. Move the denominator factors to the numerator: \(u^{-1}v^2w^{-3}z^4\). 4. Invert the coefficient and denominator powers: \(0.125p^{-2}q^3\).

Answer

1) \(7x^2y^{-3}\) 2) \(0.2a^4b^2\) 3) \(u^{-1}v^2w^{-3}z^4\) 4) \(0.125p^{-2}q^3\)
5245958
Rewrite each rational expression with no fraction bar. Use negative exponents as needed. 1) \(\frac{1}{y^{m+3}}\), where \(y\ne0\) 2) \(\frac{15a^4}{5^{-1}b^{-n}c^2}\), where \(b\ne0\) and \(c\ne0\)

Hints

- Negate the entire exponent expression when moving a power from the denominator. - Treat coefficients and variable factors separately. - Distribute the leading negative sign across \(m+3\).

Solution

1. Move the denominator power to the numerator: \(y^{-(m+3)}=y^{-m-3}\). 2. Moving the denominator factors changes their exponent signs: \(15a^4\cdot5^1b^nc^{-2}\). 3. Multiply the coefficients: \(15\cdot5=75\), so the result is \(75a^4b^nc^{-2}\).

Answer

1) \(y^{-m-3}\) 2) \(75a^4b^nc^{-2}\)
5246058
Let \(T=\frac{5a^{-n}b^2}{2c^{-3}d}\), where \(a,b,c,d\ne0\) and \(n\) is a natural number. 1. Rewrite the expression with no fraction bar, using negative exponents as needed. 2. Rewrite the expression with no negative exponents.

Hints

- Change an exponent’s sign when moving a factor across the fraction bar. - Convert \(\frac{5}{2}\) to a decimal for part 1. - In part 2, move all negative powers to the opposite side of the fraction bar.

Solution

1. Move the denominator factors to the numerator: \(T=2.5a^{-n}b^2c^3d^{-1}\). 2. Move factors with negative exponents to the denominator: \(T=\frac{5b^2c^3}{2a^nd}\).

Answer

1) \(2.5a^{-n}b^2c^3d^{-1}\) 2) \(\frac{5b^2c^3}{2a^nd}\)
5246098
Rewrite each rational expression with no fraction bar by using negative exponents. 1) \(\frac{12}{a^5}\), where \(a\ne0\) 2) \(\frac{3x^2}{4y^3}\), where \(y\ne0\) 3) \(\frac{2}{3(m+n)^4}\), where \(m+n\ne0\) 4) \(\frac{ab}{c}\), where \(c\ne0\)

Hints

- Treat every denominator factor as a factor with a negative exponent. - Constant denominators can also be written using negative exponents. - Keep parentheses around a multi-term base.

Solution

1. \(\frac{12}{a^5}=12a^{-5}\). 2. \(\frac{3x^2}{4y^3}=3\cdot4^{-1}x^2y^{-3}\). 3. \(\frac{2}{3(m+n)^4}=2\cdot3^{-1}(m+n)^{-4}\). 4. \(\frac{ab}{c}=abc^{-1}\).

Answer

1) \(12a^{-5}\) 2) \(3\cdot4^{-1}x^2y^{-3}\) 3) \(2\cdot3^{-1}(m+n)^{-4}\) 4) \(abc^{-1}\)
5103968
Order the values from least to greatest. \(A = \frac{(-1)^3}{2}\) \(B = \frac{-1^4}{-4}\) \(C = -\frac{(-1)^2}{8}\)

Hints

- Evaluate each expression separately. - In \(B\), determine whether the exponent applies to the negative sign. - Compare the resulting rational numbers on a number line or by using common denominators.

Solution

1. Evaluate \(A\): \((-1)^3 = -1\), so \(A = -\frac{1}{2}\). 2. Evaluate \(B\): the exponent applies before the leading negative sign, so \(-1^4 = -(1^4) = -1\). Thus, \(B = \frac{-1}{-4} = \frac{1}{4}\). 3. Evaluate \(C\): \((-1)^2 = 1\), so \(C = -\frac{1}{8}\). 4. Compare the values: \(-\frac{1}{2} < -\frac{1}{8} < \frac{1}{4}\). Therefore, \(A < C < B\).

Answer

\(A < C < B\)
5122308
Consider these expressions. Expression A: \((-10)^3\) Expression B: \((-1)^4 \cdot 10^4\) Expression C: \((-10) \cdot (-10) \cdot (-10) \cdot (-10) \cdot (-10)\) a) Which expression has the least value? Explain. b) Which expressions have positive values? c) What is the absolute value of Expression B?

Hints

- Recall how an even or odd exponent affects the sign of a power with a negative base. - On a number line, a negative number with greater absolute value is farther left. - Absolute value is distance from \(0\).

Solution

1. Expression A is \((-10)^3 = -1000\). 2. Expression B is \((-1)^4 \cdot 10^4 = 1 \cdot 10^4 = 10{,}000\). 3. Expression C is \((-10)^5 = -100{,}000\). 4. Since \(-100{,}000 < -1000 < 10{,}000\), Expression C has the least value. 5. Only Expression B is positive. 6. The absolute value of Expression B is \(|10{,}000| = 10{,}000\).

Answer

a) Expression C, with a value of \(-100{,}000\) b) Expression B only c) \(10{,}000\)
5122338
Consider the sequence \((-2)^1, (-2)^2, (-2)^3, (-2)^4, \ldots\). a) Calculate the first five terms. b) Determine the sign of Term 15 and Term 20 without calculating their exact values. Explain. c) What is the sign of \(-(-2)^4\)? Evaluate the expression step by step.

Hints

- Look for a pattern in the signs of consecutive terms. - Recall how even and odd exponents affect a negative base. - In part c), evaluate the power before applying the outside negative sign.

Solution

1. The first five terms are \((-2)^1 = -2\), \((-2)^2 = 4\), \((-2)^3 = -8\), \((-2)^4 = 16\), and \((-2)^5 = -32\). 2. Term 15 is \((-2)^{15}\). Since \(15\) is odd, the term is negative. Term 20 is \((-2)^{20}\). Since \(20\) is even, the term is positive. 3. First evaluate the power: \((-2)^4 = 16\). Then apply the outside negative sign: \(-16\). The expression is negative.

Answer

a) \(-2, 4, -8, 16, -32\) b) Term 15 is negative, and Term 20 is positive. c) Negative; \(-(-2)^4 = -16\)
5126778
Let \(A = x^3 \cdot x^2\), \(B = (x^2)^4\), \(C = x^9 \div x^2\), and \(D = x^5 + x^5\). Simplify each expression. Assume \(x \ne 0\) for Expression C. Which expression has the greatest value when \(x = 10\)?

Hints

- Apply the properties for multiplying, dividing, and raising powers to powers. - In Expression D, distinguish addition from multiplication. - After substitution, compare the powers of \(10\).

Solution

1. Apply the exponent properties: \(A = x^5\), \(B = x^8\), \(C = x^7\), and \(D = 2x^5\). 2. At \(x = 10\), the values are \(A = 10^5 = 100{,}000\), \(B = 10^8 = 100{,}000{,}000\), \(C = 10^7 = 10{,}000{,}000\), and \(D = 2 \cdot 10^5 = 200{,}000\). 3. Expression B has the greatest value.

Answer

\(A = x^5\) \(B = x^8\) \(C = x^7\) \(D = 2x^5\) When \(x = 10\), Expression B has the greatest value, \(100{,}000{,}000\).
5126788
Rewrite each expression as a power with base \(2\). Then identify the expression with the least value and the expression with the greatest value. (1) \(16^3\) (2) \(4^7\) (3) \(2^{11}\) (4) \(8^4\) (5) \(32^2\)

Hints

- Write \(4\), \(8\), \(16\), and \(32\) as powers of \(2\). - Use \((a^m)^n = a^{mn}\). - Once the bases match, compare the exponents.

Solution

1. Rewrite each base as a power of \(2\): (1) \((2^4)^3 = 2^{12}\), (2) \((2^2)^7 = 2^{14}\), (3) \(2^{11}\), (4) \((2^3)^4 = 2^{12}\), and (5) \((2^5)^2 = 2^{10}\). 2. Compare the exponents: \(10 < 11 < 12 < 14\). 3. Therefore, \(32^2\) has the least value, and \(4^7\) has the greatest value.

Answer

(1) \(2^{12}\) (2) \(2^{14}\) (3) \(2^{11}\) (4) \(2^{12}\) (5) \(2^{10}\) Least: \(32^2\) Greatest: \(4^7\)
5130558
Use exponent properties to simplify. Assume \(a\ne0\), \(b\ne0\), \(x\ne0\), and \(n\in\mathbb{Z}\). a) \(\frac{a^4\cdot b^{-2}}{a^{-1}\cdot b^3}\) b) \((0.2x^2)^3\cdot125x^{-6}\) c) \(\frac{x^{n+3}}{x^{n-1}}\)

Hints

- Treat each base separately. - Subtract the denominator exponent when dividing like bases. - Multiply exponents for a power of a power. - Rewrite negative exponents as reciprocals when needed.

Solution

1. For part a, subtract exponents for each base: \(a^{4-(-1)}b^{-2-3}=a^5b^{-5}=\frac{a^5}{b^5}\). 2. For part b, \((0.2x^2)^3=0.008x^6\). Then \(0.008x^6\cdot125x^{-6}=1\cdot x^0=1\). 3. For part c, \(\frac{x^{n+3}}{x^{n-1}}=x^{(n+3)-(n-1)}=x^4\).

Answer

a) \(\frac{a^5}{b^5}\) b) \(1\) c) \(x^4\)
5130568
Which of the following expressions are equivalent to \(16x^8\) for \(x \ne 0\)? Justify each choice by simplifying the expression. A: \((2x^2)^4\) B: \(8x^4 + 8x^4\) C: \(32x^9 \div (2x)\) D: \((4x^4)^2\) E: \(2 \cdot (2x^2)^3\)

Hints

- Simplify each expression until it is written in the form \(ax^n\). - Remember that adding like terms does not change the exponent. - An exponent outside parentheses applies to every factor inside the parentheses.

Solution

1. A: \((2x^2)^4 = 2^4(x^2)^4 = 16x^8\), so A is equivalent. 2. B: \(8x^4 + 8x^4 = 16x^4\), so B is not equivalent. 3. C: \(32x^9 \div (2x) = 16x^{9-1} = 16x^8\), so C is equivalent. 4. D: \((4x^4)^2 = 4^2(x^4)^2 = 16x^8\), so D is equivalent. 5. E: \(2 \cdot (2x^2)^3 = 2 \cdot 8x^6 = 16x^6\), so E is not equivalent.

Answer

A, C, and D are equivalent to \(16x^8\).
5134068
Determine which expressions have the same value. Group them and justify each group by simplifying. \(A=\left(\frac{1}{3}\right)^{-2}\) \(B=3^{-2}\) \(C=\frac{1}{9}\) \(D=9\) \(E=\frac{3^5}{3^7}\) \(F=(-3)^2\)

Hints

- Simplify every expression to a numerical value. - Distinguish a negative base from a negative exponent. - Apply the quotient rule to expression \(E\).

Solution

1. \(A=\left(\frac{1}{3}\right)^{-2}=3^2=9\). 2. \(B=3^{-2}=\frac{1}{9}\). 3. \(C=\frac{1}{9}\) and \(D=9\). 4. \(E=3^{5-7}=3^{-2}=\frac{1}{9}\). 5. \(F=(-3)^2=9\). 6. Therefore, \(A,D,F\) have value \(9\), and \(B,C,E\) have value \(\frac{1}{9}\).

Answer

Value \(9\): \(A,D,F\) Value \(\frac{1}{9}\): \(B,C,E\)
5134078
Simplify and write the result without negative exponents: \(\frac{(x^2y^{-3})^{-2}}{x^{-1}y^4}\) Assume \(x\ne0\) and \(y\ne0\).

Hints

- Apply the outer exponent to both factors inside the parentheses. - Subtract exponents when dividing powers with the same base. - Move a factor with a negative exponent across the fraction bar.

Solution

1. Apply the power of a product and power of a power rules: \((x^2y^{-3})^{-2}=x^{-4}y^6\). 2. Divide powers with the same base: \(\frac{x^{-4}y^6}{x^{-1}y^4}=x^{-4-(-1)}y^{6-4}=x^{-3}y^2\). 3. Rewrite without negative exponents: \(x^{-3}y^2=\frac{y^2}{x^3}\).

Answer

\(\frac{y^2}{x^3}\)
5134098
Simplify each expression. Write each result as a single power with no fraction bar. Use negative exponents when needed. a) \(\frac{x^7x^{-3}}{x^2}\), where \(x\ne0\) b) \((y^{-2})^4y^5\), where \(y\ne0\) c) \(\frac{b^4}{b^{-2}}\), where \(b\ne0\)

Hints

- Add exponents when multiplying powers with the same base. - Multiply exponents when raising a power to a power. - When dividing, subtract the denominator exponent.

Solution

1. For a), add exponents in the numerator and subtract the denominator exponent: \(x^{7+(-3)-2}=x^2\). 2. For b), multiply exponents, then add: \(y^{(-2)\cdot4+5}=y^{-3}\). 3. For c), subtract the exponent in the denominator: \(b^{4-(-2)}=b^6\).

Answer

a) \(x^2\) b) \(y^{-3}\) c) \(b^6\)
5134158
Assume \(a\ne0\). Five of the following expressions are equivalent to \(a^{-6}\). Identify them and briefly explain why the other two are not equivalent. 1. \(a^{-2}\cdot a^{-4}\) 2. \((a^3)^{-2}\) 3. \(\frac{a^4}{a^{10}}\) 4. \((-a)^{-6}\) 5. \(\frac{1}{a^6}\) 6. \(-a^{-6}\) 7. \((a^{-3})^{-2}\)

Hints

- Simplify the exponent in each expression. - Pay attention to whether a negative sign is part of the base or outside the power. - An even exponent removes the sign of a nonzero base.

Solution

1. Expression 1 is \(a^{-2+(-4)}=a^{-6}\). 2. Expression 2 is \(a^{3\cdot(-2)}=a^{-6}\). 3. Expression 3 is \(a^{4-10}=a^{-6}\). 4. Expression 4 equals \(a^{-6}\) because the exponent is even. 5. Expression 5 equals \(a^{-6}\) by definition. 6. Expression 6 is the opposite of \(a^{-6}\), so it is not equivalent. 7. Expression 7 is \(a^{(-3)\cdot(-2)}=a^6\), so it is not equivalent.

Answer

Expressions 1, 2, 3, 4, and 5 are equivalent to \(a^{-6}\). Expressions 6 and 7 are not.
5134198
Assume \(a\ne0\) and \(b\ne0\). Simplify completely and write the result without negative exponents: \(\frac{(3a^{-2}b)^2a^5}{9b^3}\)

Hints

- Apply the outer exponent to every factor inside the parentheses. - Combine powers with the same base. - Rewrite any remaining negative exponent as a reciprocal.

Solution

1. Apply the exponent to each factor: \((3a^{-2}b)^2=9a^{-4}b^2\). 2. Multiply by \(a^5\): \(9a^{-4}b^2a^5=9ab^2\). 3. Divide by \(9b^3\): \(\frac{9ab^2}{9b^3}=ab^{-1}\). 4. Rewrite without a negative exponent: \(ab^{-1}=\frac{a}{b}\).

Answer

\(\frac{a}{b}\)
5134218
Assume \(k\ne0\) and \(a\ne0\). Lucas and Mia simplify \(\frac{k^5k^{-2}}{k^7}\). Lucas writes \(k^{5-2-7}=k^{-4}\). Mia writes \(\frac{k^3}{k^7}=\frac{1}{k^4}\). a) Explain why their results represent the same value. b) Simplify \(\frac{(a^2)^{-3}}{a^{-4}}\) and write the result without negative exponents.

Hints

- Use the definition of a negative exponent. - Multiply exponents when raising a power to a power. - Subtract exponents when dividing powers with the same base.

Solution

1. By the definition of negative exponents, \(k^{-4}=\frac{1}{k^4}\). Therefore, both students are correct. 2. For b), \((a^2)^{-3}=a^{-6}\). 3. Divide powers with the same base: \(a^{-6}\div a^{-4}=a^{-6-(-4)}=a^{-2}\). 4. Rewrite without a negative exponent: \(a^{-2}=\frac{1}{a^2}\).

Answer

a) Both are correct because \(k^{-4}=\frac{1}{k^4}\). b) \(\frac{1}{a^2}\)
5134228
Assume \(a\ne0\). Simplify and write the result without negative exponents: \(T=\frac{(3a)^2a^{-5}}{3a^{-1}}\)

Hints

- Square both the coefficient and the variable. - Simplify the numerator before dividing. - Rewrite the final negative exponent as a reciprocal.

Solution

1. Expand the power: \((3a)^2=9a^2\). 2. Combine the factors in the numerator: \(9a^2a^{-5}=9a^{-3}\). 3. Divide by \(3a^{-1}\): \(\frac{9a^{-3}}{3a^{-1}}=3a^{-3-(-1)}=3a^{-2}\). 4. Rewrite without a negative exponent: \(3a^{-2}=\frac{3}{a^2}\).

Answer

\(\frac{3}{a^2}\)
5134248
Assume \(x\ne0\) and \(y\ne0\). Simplify each expression. Write each result as a power with a negative exponent and no fraction bar. a) \(\frac{x^3x^{-7}}{x^{-2}}\) b) \((y^{-2})^{-3}y^{-10}\)

Hints

- Combine the numerator before dividing in part a). - Multiply exponents when raising a power to a power. - Keep careful track of subtracting a negative exponent.

Solution

1. For a), combine the numerator and then divide: \(x^{3+(-7)-(-2)}=x^{-2}\). 2. For b), raise the power to a power, then multiply: \(y^{(-2)\cdot(-3)+(-10)}=y^{6-10}=y^{-4}\).

Answer

a) \(x^{-2}\) b) \(y^{-4}\)
5134278
Simplify each expression. Give each result as a reduced fraction or an integer. a) \(8\cdot2^{-5}\) b) \(\left(\frac{3}{4}\right)^2\cdot\left(\frac{4}{3}\right)^{-1}\) c) \(0.25^{-1}\cdot4^{-2}\) d) \(\frac{7^2\cdot7^{-5}}{7^{-3}}\)

Hints

- Rewrite numbers using a common base when possible. - Convert a terminating decimal to a fraction before applying exponent rules. - A negative exponent on a fraction gives the reciprocal.

Solution

1. For a), write \(8=2^3\): \(2^3\cdot2^{-5}=2^{-2}=\frac{1}{4}\). 2. For b), \(\left(\frac{4}{3}\right)^{-1}=\frac{3}{4}\), so the product is \(\left(\frac{3}{4}\right)^3=\frac{27}{64}\). 3. For c), write \(0.25=\frac{1}{4}\): \(\left(\frac{1}{4}\right)^{-1}4^{-2}=4^1\cdot4^{-2}=\frac{1}{4}\). 4. For d), \(7^{2-5-(-3)}=7^0=1\).

Answer

a) \(\frac{1}{4}\) b) \(\frac{27}{64}\) c) \(\frac{1}{4}\) d) \(1\)
5134338
Assume all variables are nonzero. Simplify and write each result as a fraction or a power with a positive exponent. a) \(\frac{z^{-3}z^7}{z^2}\) b) \(\left(\frac{x^2}{y}\right)^{-3}\) c) \((3a^{-2})^2a^5\)

Hints

- Combine powers with the same base. - A negative exponent on a fraction reverses the fraction. - Apply an exponent to every factor inside parentheses.

Solution

1. For a), \(z^{-3+7-2}=z^2\). 2. For b), take the reciprocal and cube: \(\left(\frac{y}{x^2}\right)^3=\frac{y^3}{x^6}\). 3. For c), \((3a^{-2})^2a^5=9a^{-4}a^5=9a\).

Answer

a) \(z^2\) b) \(\frac{y^3}{x^6}\) c) \(9a\)
5134368
Assume \(y\ne0\). Consider \(T=\frac{y^{-3}y^5}{y^{-2}}\). Lucas claims the result is \(y^0=1\). Sarah claims the result is \(y^4\). Determine who is correct and justify your answer step by step.

Hints

- Add exponents when multiplying powers with the same base. - Subtract the denominator exponent when dividing. - Be careful when subtracting a negative number.

Solution

1. Simplify the numerator: \(y^{-3}y^5=y^{-3+5}=y^2\). 2. Divide by \(y^{-2}\): \(y^{2-(-2)}=y^4\). 3. Sarah is correct. Lucas incorrectly treated subtraction of \(-2\) as subtraction of \(2\).

Answer

Sarah is correct; the expression simplifies to \(y^4\).
5134458
Assume all variables are nonzero. Simplify completely and write each result without negative exponents. a) \((3y^2)^{-2}\cdot27y^5\) b) \(\left(\frac{k}{2}\right)^{-3}k^2\) c) \(\frac{m^{-4}}{(m^{-2})^3}\)

Hints

- A negative exponent on a fraction reverses the fraction. - Apply an exponent to every factor in parentheses. - Subtract exponents carefully when dividing.

Solution

1. For a), \((3y^2)^{-2}=\frac{1}{9y^4}\), so \(\frac{27y^5}{9y^4}=3y\). 2. For b), \(\left(\frac{k}{2}\right)^{-3}=\left(\frac{2}{k}\right)^3=\frac{8}{k^3}\), so the product is \(\frac{8}{k}\). 3. For c), \((m^{-2})^3=m^{-6}\), so \(m^{-4-(-6)}=m^2\).

Answer

a) \(3y\) b) \(\frac{8}{k}\) c) \(m^2\)
5134468
Assume all variables are nonzero. Simplify and write each result without negative exponents. a) \(\frac{(u^3v^{-2})^{-1}}{u^{-4}v}\) b) \(\left(\frac{2}{x^2}\right)^{-2}(xy^0)^{-3}\)

Hints

- Simplify the numerator and denominator separately. - Recall that a nonzero number to the zero power equals \(1\). - Rewrite negative powers before combining factors.

Solution

1. For a), \((u^3v^{-2})^{-1}=u^{-3}v^2\). Dividing by \(u^{-4}v\) gives \(u^{-3-(-4)}v^{2-1}=uv\). 2. For b), \(\left(\frac{2}{x^2}\right)^{-2}=\frac{x^4}{4}\), and \((xy^0)^{-3}=x^{-3}\) because \(y^0=1\). 3. Multiply: \(\frac{x^4}{4}x^{-3}=\frac{x}{4}\).

Answer

a) \(uv\) b) \(\frac{x}{4}\)
5134908
Assume all variables are nonzero. Simplify and write each result without negative exponents. a) \(\left(\frac{2a}{b^2}\right)^3\left(\frac{b}{a}\right)^4\) b) \(\left(\left(\frac{x}{y}\right)^{-2}\right)^3\div\left(\frac{y}{x}\right)^4\)

Hints

- Apply each exponent to the coefficient and every variable factor. - Multiply exponents when raising a power to a power. - Combine powers with the same fractional base.

Solution

1. For a), \(\left(\frac{2a}{b^2}\right)^3=\frac{8a^3}{b^6}\) and \(\left(\frac{b}{a}\right)^4=\frac{b^4}{a^4}\). 2. Multiply and simplify: \(\frac{8a^3b^4}{b^6a^4}=\frac{8}{ab^2}\). 3. For b), \(\left(\left(\frac{x}{y}\right)^{-2}\right)^3=\left(\frac{x}{y}\right)^{-6}=\left(\frac{y}{x}\right)^6\). 4. Divide powers with the same base: \(\left(\frac{y}{x}\right)^{6-4}=\frac{y^2}{x^2}\).

Answer

a) \(\frac{8}{ab^2}\) b) \(\frac{y^2}{x^2}\)
5134918
Assume \(u\), \(v\), and \(w\) are nonzero. Simplify completely: \(\left(\frac{u^2v}{w}\right)^{-3}\div\left(\frac{w^2}{uv^2}\right)^2\cdot\frac{w}{u^5}\)

Hints

- Work from left to right. - Rewrite negative exponents and division before combining factors. - Combine powers of each variable separately.

Solution

1. Rewrite the first factor: \(\left(\frac{u^2v}{w}\right)^{-3}=\frac{w^3}{u^6v^3}\). 2. Rewrite division by the second factor as multiplication by its reciprocal: \(\frac{w^3}{u^6v^3}\cdot\frac{u^2v^4}{w^4}\). 3. Simplify the first two factors: \(\frac{v}{u^4w}\). 4. Multiply by \(\frac{w}{u^5}\): \(\frac{v}{u^4w}\cdot\frac{w}{u^5}=\frac{v}{u^9}\).

Answer

\(\frac{v}{u^9}\)
5135388
Assume all variables are nonzero. Simplify and write each result without negative exponents. a) \((2a)^{-3}\cdot8a^4\) b) \(\frac{x^{-2}y^2}{(xy)^{-1}}\) c) \(\left(\frac{b^2}{3}\right)^{-2}b^4\)

Hints

- Apply a negative exponent to every factor inside parentheses. - Subtract exponents when dividing powers with the same base. - Recall that a nonzero base to the zero power equals \(1\).

Solution

1. For a), \((2a)^{-3}=\frac{1}{8}a^{-3}\), so the product is \(a\). 2. For b), \((xy)^{-1}=x^{-1}y^{-1}\). Dividing gives \(x^{-2-(-1)}y^{2-(-1)}=x^{-1}y^3=\frac{y^3}{x}\). 3. For c), \(\left(\frac{b^2}{3}\right)^{-2}=9b^{-4}\), so multiplying by \(b^4\) gives \(9\).

Answer

a) \(a\) b) \(\frac{y^3}{x}\) c) \(9\)
5139238
Simplify the expression for \(x \ne 0\). Use properties of exponents and the distributive property. \(\frac{(2x^3)^2}{x^4} - 3x(x - 2)\)

Hints

- Which exponent property applies when a power is raised to another power? - What happens to the exponents when powers with the same base are divided? - Pay close attention to the signs when distributing \(-3x\).

Solution

1. Simplify the power in the numerator: \((2x^3)^2 = 2^2(x^3)^2 = 4x^6\). 2. Divide powers with the same base: \(\frac{4x^6}{x^4} = 4x^{6-4} = 4x^2\). 3. Distribute: \(-3x(x - 2) = -3x^2 + 6x\). 4. Combine like terms: \(4x^2 - 3x^2 + 6x = x^2 + 6x\).

Answer

\(x^2 + 6x\)
5139288
Use exponent properties. Assume \(x\ne0\) in part b. a) Evaluate and compare \(2^{-3}\) and \(-2^3\). b) Simplify \(\frac{(x^2)^3}{x^4\cdot x^{-1}}\). c) Evaluate \(\frac{15^3}{5^3}\) using the quotient property. d) Find \(x\) if \(2^x=\frac{1}{32}\).

Hints

- A negative exponent produces a reciprocal. - Rewrite \(32\) as a power of \(2\). - Use the quotient property when two powers have the same exponent.

Solution

1. \(2^{-3}=\frac{1}{8}=0.125\), while \(-2^3=-8\). Therefore, \(2^{-3}>-2^3\). 2. \((x^2)^3=x^6\), and \(x^4\cdot x^{-1}=x^3\). Thus \(\frac{x^6}{x^3}=x^3\). 3. \(\frac{15^3}{5^3}=\left(\frac{15}{5}\right)^3=3^3=27\). 4. Since \(\frac{1}{32}=2^{-5}\), matching exponents gives \(x=-5\).

Answer

a) \(2^{-3}=0.125>-8=-2^3\) b) \(x^3\) c) \(27\) d) \(x=-5\)
5139298
Use exponent properties. Assume \(a\ne0\) and \(b\ne0\) in part a. a) Simplify \(\frac{18a^5b^{-2}}{3(ab)^2}\). Write the answer without negative exponents. b) Find \(n\) if \(\frac{5^8}{5^n}=125\). c) Show that \(\frac{2^k\cdot2^{k+1}}{4^k}\) has the same numerical value for every positive integer \(k\), and find that value.

Hints

- Expand powers of products before combining like bases. - Rewrite \(125\) as a power of \(5\). - In part c, rewrite every power using base \(2\).

Solution

1. Expand the denominator: \(3(ab)^2=3a^2b^2\). Then \(\frac{18a^5b^{-2}}{3a^2b^2}=6a^3b^{-4}=\frac{6a^3}{b^4}\). 2. Since \(125=5^3\), \(5^{8-n}=5^3\). Therefore, \(8-n=3\) and \(n=5\). 3. Rewrite \(4^k=(2^2)^k=2^{2k}\). The numerator is \(2^{2k+1}\), so the quotient is \(2^{2k+1-2k}=2\).

Answer

a) \(\frac{6a^3}{b^4}\) b) \(n=5\) c) \(2\)
5139558
A student simplifies \(4x^2 \cdot (3x)^2\) as follows: \(4x^2 \cdot (3x)^2 = 4x^2 \cdot 3x^2 = 12x^4\) Explain the error in the first step and find the correct result.

Hints

- Determine every factor to which the exponent applies. - Does the exponent apply to the entire quantity in parentheses? - Multiply coefficients separately from powers of \(x\).

Solution

1. The exponent applies to both factors inside the parentheses. The student squared \(x\) but did not square \(3\). 2. Correctly expand the power: \((3x)^2 = 3^2x^2 = 9x^2\). 3. Multiply: \(4x^2 \cdot 9x^2 = 36x^4\).

Answer

The student failed to square the coefficient \(3\). The correct result is \(36x^4\).
5139568
Let \(T_1 = (2a)^3\) and \(T_2 = 2a^3\). a) Evaluate both expressions when \(a = 3\). b) Use the order of operations to explain why the results are different.

Hints

- Substitute \(a = 3\) and follow the order of operations. - Parentheses identify the complete base of a power. - Exponents are evaluated before multiplication when there are no grouping symbols.

Solution

1. Substitute \(a = 3\): \(T_1 = (2 \cdot 3)^3 = 6^3 = 216\). 2. For the second expression, \(T_2 = 2 \cdot 3^3 = 2 \cdot 27 = 54\). 3. In \(T_1\), the parentheses make \(2a\) the entire base, so the product is cubed. In \(T_2\), the exponent applies only to \(a\), and multiplication by \(2\) occurs afterward.

Answer

a) \(T_1 = 216\) and \(T_2 = 54\) b) In \(T_1\), the entire product \(2a\) is cubed. In \(T_2\), only \(a\) is cubed before multiplying by \(2\).
5140458
Assume \(a\ne0\). Simplify and write the result without a fraction bar, using a negative exponent: \(\frac{a^{-3}(a^2)^{-2}}{a^{-5}}\)

Hints

- Multiply exponents when raising a power to a power. - Add exponents in the numerator. - Subtract the denominator exponent carefully.

Solution

1. Raise the power to a power: \((a^2)^{-2}=a^{-4}\). 2. Combine the numerator: \(a^{-3}a^{-4}=a^{-7}\). 3. Divide: \(a^{-7}\div a^{-5}=a^{-7-(-5)}=a^{-2}\).

Answer

\(a^{-2}\)
5140468
Consider the expressions I. \(10^{-2}\), II. \((-10)^{-2}\), and III. \(-10^{-2}\). a) Find the exact decimal value of each expression. b) Order the expressions from least to greatest using \(<\) or \(=\).

Hints

- Identify whether the negative sign is part of the base. - Rewrite each negative exponent as a reciprocal. - Compare the resulting decimal values.

Solution

1. \(10^{-2}=\frac{1}{100}=0.01\). 2. \((-10)^{-2}=\frac{1}{(-10)^2}=0.01\). 3. \(-10^{-2}=-\frac{1}{100}=-0.01\). 4. Therefore, \(-0.01<0.01=0.01\), so III \(<\) I \(=\) II.

Answer

a) I: \(0.01\); II: \(0.01\); III: \(-0.01\) b) III \(<\) I \(=\) II
5141358
Simplify each expression. a) Evaluate \((-4)^2\), \(-4^2\), and \((-2)^3\). b) Simplify \(x^2 \cdot x^5 \cdot x\). c) Simplify \((y^8 \div y^3) \cdot y^2\) for \(y \ne 0\).

Hints

- Determine whether a negative sign is inside or outside the base. - A variable with no written exponent has exponent \(1\). - Add exponents when multiplying powers with the same base. - Subtract exponents when dividing powers with the same nonzero base.

Solution

1. a) \((-4)^2 = 16\), \(-4^2 = -(4^2) = -16\), and \((-2)^3 = -8\). 2. b) Since \(x = x^1\), add the exponents: \(x^{2+5+1} = x^8\). 3. c) First divide: \(y^8 \div y^3 = y^{8-3} = y^5\). Then multiply: \(y^5 \cdot y^2 = y^7\).

Answer

a) \(16, -16, -8\) b) \(x^8\) c) \(y^7\)
5141368
Simplify each expression. a) \(5a^3 \cdot 3a^2\) b) \(18b^6 \div (3b^2 \cdot 2b)\), where \(b \ne 0\) c) \(7z^4 - 2z^4 + z^4\)

Hints

- Work with coefficients and powers separately when multiplying. - In part b), simplify the expression in parentheses first. - Terms can be combined by addition or subtraction only when their variable parts match.

Solution

1. a) Multiply the coefficients and add the exponents: \(5 \cdot 3 = 15\) and \(a^3 \cdot a^2 = a^5\). The result is \(15a^5\). 2. b) First simplify the divisor: \(3b^2 \cdot 2b = 6b^3\). Then \(18b^6 \div 6b^3 = 3b^{6-3} = 3b^3\). 3. c) Combine like terms: \((7 - 2 + 1)z^4 = 6z^4\).

Answer

a) \(15a^5\) b) \(3b^3\) c) \(6z^4\)
5141778
Assume \(x\ne0\). Simplify and write the result as a single power with no fraction bar: \(\frac{x^4x^{-7}}{(x^{-2})^2}\)

Hints

- Simplify the numerator and denominator separately. - Multiply exponents in the denominator. - Subtract the denominator exponent when dividing.

Solution

1. Simplify the numerator: \(x^4x^{-7}=x^{-3}\). 2. Simplify the denominator: \((x^{-2})^2=x^{-4}\). 3. Divide: \(x^{-3}\div x^{-4}=x^{-3-(-4)}=x\).

Answer

\(x\)
5141788
Assume \(a\ne0\) and \(b\ne0\). Simplify and write the result without negative exponents: \(\left(\frac{a^2}{b}\right)^{-2}(ab^3)^{-1}\)

Hints

- A negative exponent on a fraction reverses the fraction. - Apply the exponent to every factor in a product. - Cancel common powers at the end.

Solution

1. Reverse the first fraction and square: \(\left(\frac{a^2}{b}\right)^{-2}=\frac{b^2}{a^4}\). 2. Rewrite the second factor: \((ab^3)^{-1}=\frac{1}{ab^3}\). 3. Multiply: \(\frac{b^2}{a^4}\cdot\frac{1}{ab^3}=\frac{1}{a^5b}\).

Answer

\(\frac{1}{a^5b}\)
5141808
Simplify each expression using exponent properties, then find its value. a) \(0.25^{-3}\cdot4^{-5}\cdot2^4\) b) \((-6)^3\div3^3\cdot(-2)^{-1}\)

Hints

- Rewrite the decimal as a fraction or a power with a useful base. - Combine powers with the same exponent when possible. - Pay attention to whether a negative sign is part of the base.

Solution

1. For a), \(0.25=4^{-1}\), so \(0.25^{-3}=4^3\), and \(2^4=4^2\). Thus \(4^{3-5+2}=4^0=1\). 2. For b), \((-6)^3\div3^3=(-2)^3\). Then \((-2)^3\cdot(-2)^{-1}=(-2)^2=4\).

Answer

a) \(1\) b) \(4\)
5141818
Evaluate using exponent properties. Show intermediate steps. \(\frac{12^3\cdot2^{-4}}{3^2\cdot2^{-1}}\)

Hints

- Factor \(12\) into powers of \(2\) and \(3\). - Simplify the numerator first. - Subtract the denominator exponents when dividing.

Solution

1. Factor \(12=3\cdot2^2\): \(12^3=3^3\cdot2^6\). 2. The numerator becomes \(3^3\cdot2^{6-4}=3^3\cdot2^2\). 3. Divide by the denominator: \(3^{3-2}\cdot2^{2-(-1)}=3\cdot2^3\). 4. Evaluate: \(3\cdot8=24\).

Answer

\(24\)
5149168
Consider \(k(x)=3x^{-2}\) with domain \(\mathbb{R}\setminus\{0\}\). a) Find the x-values for which \(k(x)=\frac{1}{12}\). b) Explain why no point on the graph has a negative y-coordinate. c) How does the function value change when the input is doubled? Show this generally or with an example.

Hints

- Use the definition \(x^{-n}=\frac{1}{x^n}\). - What values can \(x^2\) have when \(x\ne0\)? - Compare \((2x)^2\) with \(x^2\).

Solution

1. Rewrite and solve: \(3x^{-2}=\frac{1}{12}\) means \(\frac{3}{x^2}=\frac{1}{12}\). Cross-multiplying gives \(x^2=36\), so \(x=-6\) or \(x=6\). 2. For every \(x\ne0\), \(x^{-2}=\frac{1}{x^2}>0\). Multiplying by \(3\) keeps the value positive. 3. \(k(2x)=3(2x)^{-2}=3\cdot2^{-2}x^{-2}=\frac{1}{4}k(x)\). Doubling the input divides the output by \(4\).

Answer

a) \(x=-6\) and \(x=6\) b) Since \(x^{-2}=\frac{1}{x^2}>0\) for \(x\ne0\), every function value is positive. c) The function value is divided by \(4\).
5149398
Simplify and write each answer without negative exponents. Assume \(a\ne0\), \(b\ne0\), \(x\ne0\), and \(y\ne0\). a) \(\frac{15a^4\cdot a^{-7}}{3a^{-2}}\) b) \((2b^{-2})^3\cdot(b^2)^2\) c) \(\left(\frac{x}{y^2}\right)^{-2}\cdot x^{-1}\)

Hints

- Apply an outside exponent to every factor in parentheses. - A negative exponent reverses a fraction. - Combine like bases only after expanding the powers.

Solution

1. Divide coefficients and combine exponents: \(5a^{4-7-(-2)}=5a^{-1}=\frac{5}{a}\). 2. \((2b^{-2})^3=8b^{-6}\) and \((b^2)^2=b^4\). Their product is \(8b^{-2}=\frac{8}{b^2}\). 3. \(\left(\frac{x}{y^2}\right)^{-2}=\frac{y^4}{x^2}\). Multiplying by \(x^{-1}\) gives \(\frac{y^4}{x^3}\).

Answer

a) \(\frac{5}{a}\) b) \(\frac{8}{b^2}\) c) \(\frac{y^4}{x^3}\)
5149408
Simplify completely without negative exponents. Assume \(p\ne0\), \(q\ne0\), \(x\ne0\), \(a\ne0\), and \(b\ne0\). a) \(\frac{(3p^{-2}q)^2}{9p^{-4}q^3}\) b) \(\frac{(-x^2)^{-3}\cdot x^8}{x^{-2}}\) c) \(\left(\frac{2a^{-3}}{b^2}\right)^{-2}\cdot\frac{a^{-6}}{b^4}\)

Hints

- Expand powers of products and quotients first. - Track the sign when a negative base has an odd exponent. - Look for factors that cancel after exponent properties are applied.

Solution

1. The numerator in part a is \(9p^{-4}q^2\). Dividing gives \(p^0q^{-1}=\frac{1}{q}\). 2. \((-x^2)^{-3}=-x^{-6}\). Then \(\frac{-x^{-6}\cdot x^8}{x^{-2}}=-x^{2-(-2)}=-x^4\). 3. \(\left(\frac{2a^{-3}}{b^2}\right)^{-2}=\frac{a^6b^4}{4}\). Multiplying by \(\frac{a^{-6}}{b^4}\) gives \(\frac{1}{4}\).

Answer

a) \(\frac{1}{q}\) b) \(-x^4\) c) \(\frac{1}{4}\)
5149958
A jeweler makes pieces shaped like regular tetrahedra. The volume of a regular tetrahedron with edge length \(a\) is \(V=\frac{\sqrt{2}}{12}a^3\). a) A customer wants an edge length of \(12\,\text{mm}\) instead of the standard \(10\,\text{mm}\). By what percent does the volume increase? b) Explain generally how the volume changes when the edge length is tripled.

Hints

- Identify the power of \(a\) in the volume formula. - Compare the new and original volumes using a ratio. - Convert a growth factor into a percent increase by subtracting \(1\).

Solution

1. Since the volume is proportional to the cube of the edge length, \(\frac{V_{\text{new}}}{V_{\text{old}}}=\left(\frac{12}{10}\right)^3\). 2. \(\left(\frac{12}{10}\right)^3=1.2^3=1.728\). 3. A scale factor of \(1.728\) represents an increase of \((1.728-1)\cdot100\%=72.8\%\). 4. If the edge length is tripled, \(V_{\text{new}}=\frac{\sqrt{2}}{12}(3a)^3=27V\). The volume is multiplied by \(27\).

Answer

a) The volume increases by \(72.8\%\). b) The volume is multiplied by \(27\).
5154258
Use exponent properties to simplify. Assume \(a\ne0\), \(b\ne0\), \(x\ne0\), and \(n\in\mathbb{Z}\). a) \(\frac{a^{2n+1}\cdot a^{n-2}}{a^{3n-1}}\) b) \((2b^3)^{-2}\cdot4b^6\) c) \(\frac{(-x)^4\cdot x^{-2}}{x^5}\)

Hints

- Combine variable expressions in exponents just as you combine numerical exponents. - A zero exponent gives \(1\) for a nonzero base. - Determine the sign before combining powers.

Solution

1. The numerator exponent in part a is \((2n+1)+(n-2)=3n-1\). Dividing by \(a^{3n-1}\) gives \(a^0=1\). 2. \((2b^3)^{-2}=\frac{1}{4}b^{-6}\). Multiplying by \(4b^6\) gives \(1\). 3. Since \((-x)^4=x^4\), the quotient is \(x^{4-2-5}=x^{-3}=\frac{1}{x^3}\).

Answer

a) \(1\) b) \(1\) c) \(\frac{1}{x^3}\)
5155338
Use exponent properties to simplify. Write answers without negative exponents. Assume \(x\ne0\) in part a and \(a\ne0\), \(b\ne0\) in part b. a) \(\frac{x^8\cdot x^{-5}}{x^2}\) b) \(\frac{(a^3b^{-2})^2}{a^4b^{-4}}\) c) \((4\times10^5)(0.25\times10^{-8})\)

Hints

- Combine like bases by adding or subtracting exponents. - Apply the outside exponent before simplifying a quotient. - In scientific notation, handle the decimal factors and powers of ten separately.

Solution

1. \(\frac{x^8\cdot x^{-5}}{x^2}=x^{8-5-2}=x\). 2. The numerator is \(a^6b^{-4}\). Dividing by \(a^4b^{-4}\) gives \(a^2\). 3. Multiply the numerical factors and combine powers of ten: \((4\cdot0.25)\times10^{5-8}=10^{-3}=\frac{1}{1000}=0.001\).

Answer

a) \(x\) b) \(a^2\) c) \(\frac{1}{1000}\), or \(0.001\)
5155348
Let \(n\) be an integer and let \(y\) be a nonzero real number. Consider \(T=\frac{(y^n)^2}{y^4\cdot y^2}\). a) Simplify \(T\) to a single power of \(y\) whose exponent depends on \(n\). b) For what value of \(n\) is \(T=1\) for every nonzero real value of \(y\)? Justify your answer using exponent properties. c) Find the value of \(T\) when \(n=4\) and \(y=3\).

Hints

- Simplify the numerator and denominator separately using exponent properties. - A nonzero base raised to the zero power equals \(1\). - Substitute into the simplified expression for part c.

Solution

1. Use the power-of-a-power property: \((y^n)^2=y^{2n}\). Combine the denominator: \(y^4\cdot y^2=y^6\). Therefore, \(T=\frac{y^{2n}}{y^6}=y^{2n-6}\). 2. For \(T\) to equal \(1\) for every nonzero \(y\), the exponent must be \(0\). Solve \(2n-6=0\) to get \(n=3\). 3. When \(n=4\), \(T=y^{2(4)-6}=y^2\). For \(y=3\), \(T=3^2=9\).

Answer

a) \(y^{2n-6}\) b) \(n=3\) c) \(9\)
5223808
Answer each question by expanding powers as products. 1) Is \(5a^2\) equivalent to \((5a)^2\)? Explain. 2) A student says, “When I multiply \(x^2\) by \(x^4\), I get \(x^8\) because \(2 \cdot 4 = 8\).” Evaluate the claim. 3) Rewrite \(z \cdot z \cdot w \cdot z \cdot w \cdot w\) using exponents.

Hints

- Expand each power as repeated multiplication. - Identify whether a coefficient is inside or outside the base. - Count how many times each variable appears as a factor.

Solution

1. \(5a^2 = 5 \cdot a \cdot a\), while \((5a)^2 = (5a)(5a) = 25a^2\). The expressions are not equivalent. 2. \(x^2 \cdot x^4\) contains six factors of \(x\), so it equals \(x^6\). The claim is false because exponents are added when powers with the same base are multiplied. 3. The product has three factors of \(z\) and three factors of \(w\), so it is \(z^3w^3\).

Answer

1) No; \(5a^2\) and \((5a)^2 = 25a^2\) are not equivalent. 2) False; \(x^2 \cdot x^4 = x^6\). 3) \(z^3w^3\)
5223888
Complete each task. 1) Write \((3y)(3y)\) using exponent notation, first with parentheses and then without parentheses. 2) Evaluate \(2x^3\) and \((2x)^3\) when \(x = 3\). 3) Rewrite \(m \cdot m \cdot m + n \cdot n\) using exponents.

Hints

- A power outside parentheses applies to every factor inside. - Follow the order of operations when substituting. - Count repeated factors separately in each term.

Solution

1. The repeated factor is \(3y\), so \((3y)(3y) = (3y)^2 = 9y^2\). 2. \(2x^3 = 2 \cdot 3^3 = 54\), while \((2x)^3 = (2 \cdot 3)^3 = 216\). 3. The products become \(m^3 + n^2\).

Answer

1) \((3y)^2 = 9y^2\) 2) \(54\) and \(216\) 3) \(m^3 + n^2\)
5223928
Lina says, “\(3x^2\) means the same thing as \(x \cdot x \cdot x + x \cdot x \cdot x\).” Check her claim. Rewrite both expressions in expanded form and in concise form, and explain her error.

Hints

- A coefficient tells how many equal terms are added. - An exponent tells how many equal factors are multiplied. - Substitute a simple value such as \(x = 2\) as a check.

Solution

1. Expand \(3x^2\) as repeated addition: \(3x^2 = x \cdot x + x \cdot x + x \cdot x\). 2. Each product in the second expression is \(x^3\), and it appears twice, so \(x \cdot x \cdot x + x \cdot x \cdot x = 2x^3\). 3. Since \(3x^2\) and \(2x^3\) are not equivalent, Lina is incorrect. She switched the roles of the coefficient and exponent.

Answer

Lina is incorrect. \(3x^2 = x \cdot x + x \cdot x + x \cdot x\), while \(x \cdot x \cdot x + x \cdot x \cdot x = 2x^3\). She confused the coefficient with the exponent.
5224008
Let \(T_1 = (n + 3)^2\) and \(T_2 = n^2 + 3^2\). 1) Describe in words how each expression is evaluated. 2) Evaluate both expressions for \(n = 2\) and \(n = 5\). Are the expressions equivalent? 3) A square with side length \(n\,\text{cm}\) has each side increased by \(3\,\text{cm}\). Which expression represents the area of the new square? Explain.

Hints

- Pay attention to which quantity the exponent applies to. - Equivalent expressions must have the same value for every allowable input. - The area of a square is the square of its side length.

Solution

1. For \(T_1\), add \(n\) and \(3\), then square the sum. For \(T_2\), square \(n\) and \(3\) separately, then add. 2. At \(n = 2\), \(T_1 = 25\) and \(T_2 = 13\). At \(n = 5\), \(T_1 = 64\) and \(T_2 = 34\). Since the values differ for the same inputs, the expressions are not equivalent. 3. The new side length is \(n + 3\), so the area is \((n + 3)^2\,\text{cm}^2\). Thus, \(T_1\) represents the area.

Answer

1) \(T_1\) is the square of a sum; \(T_2\) is a sum of squares. 2) For \(n = 2\): \(T_1 = 25\), \(T_2 = 13\). For \(n = 5\): \(T_1 = 64\), \(T_2 = 34\). They are not equivalent. 3) \(T_1\); the area is \((n + 3)^2\,\text{cm}^2\).
5226918
Evaluate each power. 1) \((-8)^2\) 2) \((-3)^3\) 3) \(\left(-\frac{2}{5}\right)^2\) 4) \((-0.1)^3\) 5) \(\left(-1\frac{1}{2}\right)^2\)

Hints

- A negative base raised to an even power gives a positive result. - A negative base raised to an odd power gives a negative result. - Convert a mixed number to an improper fraction before raising it to a power.

Solution

1. \((-8)^2 = 64\). 2. \((-3)^3 = -27\). 3. \(\left(-\frac{2}{5}\right)^2 = \frac{4}{25}\). 4. \((-0.1)^3 = -0.001\). 5. Convert the mixed number: \(-1\frac{1}{2} = -\frac{3}{2}\). Then \(\left(-\frac{3}{2}\right)^2 = \frac{9}{4} = 2\frac{1}{4}\).

Answer

1) \(64\) 2) \(-27\) 3) \(\frac{4}{25}\) 4) \(-0.001\) 5) \(2\frac{1}{4}\)
5227378
Let \(A = (-x)^n\) and \(B = -x^n\). a) Evaluate both expressions for \(x = 5\) and \(n = 2\). Are they equal? b) Evaluate both expressions for \(x = 5\) and \(n = 3\). What do you notice? c) For which exponents \(n\)—even or odd—is \((-x)^n = -x^n\) true for every \(x\)? Explain.

Hints

- Identify whether the negative sign is inside or outside the base. - Track the sign of a product with an even or odd number of negative factors. - Compare the order of operations in the two expressions.

Solution

1. For \(n = 2\), \(A = (-5)^2 = 25\) and \(B = -5^2 = -25\). They are not equal. 2. For \(n = 3\), \(A = (-5)^3 = -125\) and \(B = -5^3 = -125\). They are equal. 3. When \(n\) is odd, a product of \(n\) negative factors is negative, so \((-x)^n = -x^n\) for every \(x\).

Answer

a) \(A = 25\), \(B = -25\); they are not equal. b) \(A = -125\), \(B = -125\); they are equal. c) The equation is true for every odd exponent \(n\).
5227388
Simplify each expression as one power or as the negative of one power. a) \((-a)^2 \cdot a^4\) b) \((-a)^3 \cdot a^3\) c) \(x^7 \div (-x)^4\), where \(x \ne 0\) d) \((-y)^2 \cdot (-y)^3\)

Hints

- First determine whether each power of a negative base is positive or negative. - Add exponents when multiplying powers with the same base. - Subtract exponents when dividing powers with the same nonzero base.

Solution

1. a) \((-a)^2 = a^2\), so \(a^2 \cdot a^4 = a^6\). 2. b) \((-a)^3 = -a^3\), so \(-a^3 \cdot a^3 = -a^6\). 3. c) \((-x)^4 = x^4\), so \(x^7 \div x^4 = x^3\). 4. d) Add the exponents on the common base: \((-y)^5 = -y^5\).

Answer

a) \(a^6\) b) \(-a^6\) c) \(x^3\) d) \(-y^5\)
5230108
For each expression, determine whether some rational value of \(a\) and, when needed, \(b\) can make the result negative. Explain. a) \(a^2 + 5\) b) \((a + b)^2\) c) \(a^3\) d) \(a^2 - 10\) e) \(-(a - 2)^2 - 1\)

Hints

- Test positive values, negative values, and \(0\). - Compare the signs of even and odd powers. - The least possible value of a square is \(0\).

Solution

1. a) No. Since \(a^2 \ge 0\), \(a^2 + 5 \ge 5\). 2. b) No. A square is never negative. 3. c) Yes. For example, \((-1)^3 = -1\). 4. d) Yes. For example, \(0^2 - 10 = -10\). 5. e) Yes. Since \((a - 2)^2 \ge 0\), the expression is always at most \(-1\), so it is always negative.

Answer

a) No b) No c) Yes; for example, \(a = -1\) d) Yes; for example, \(a = 0\) e) Yes; the expression is always negative.
5230118
Let \(T_1(x) = 3x^2 + 10\) and \(T_2(x) = 2x^3\). a) Evaluate both expressions for \(x = 4\) and \(x = -4\). b) Which expression has the same value when the sign of the input is reversed? Explain using exponent properties.

Hints

- Compare even and odd powers of opposite numbers. - Substitute carefully, including parentheses around negative inputs. - Determine which power changes sign when the input changes sign.

Solution

1. \(T_1(4) = 3 \cdot 4^2 + 10 = 58\), and \(T_1(-4) = 3 \cdot (-4)^2 + 10 = 58\). 2. \(T_2(4) = 2 \cdot 4^3 = 128\), and \(T_2(-4) = 2 \cdot (-4)^3 = -128\). 3. \(T_1\) is unchanged because squaring a number and its opposite gives the same value. Cubing preserves the sign, so \(T_2\) changes sign.

Answer

a) \(T_1(4) = 58\), \(T_1(-4) = 58\); \(T_2(4) = 128\), \(T_2(-4) = -128\) b) \(T_1\), because \(x^2\) has the same value for opposite inputs.
5230128
Let \(A(z) = z^4 - 5z^2\) and \(B(z) = z^3 - z\). a) Evaluate both expressions for \(z = 3\) and \(z = -3\). b) Explain why opposite inputs always give equal outputs for \(A\), but generally give opposite outputs for \(B\). c) Find \(B(2)\) and \(B(-2)\). Can adding the same constant to \(B(z)\) make these two outputs equal? Explain.

Hints

- Compare the effects of even and odd exponents on signs. - Calculate both values before reasoning about the constant. - Adding the same number to two values does not change their difference.

Solution

1. \(A(3) = 81 - 45 = 36\) and \(A(-3) = 81 - 45 = 36\). 2. \(B(3) = 27 - 3 = 24\) and \(B(-3) = -27 + 3 = -24\). 3. Every power in \(A\) has an even exponent, so \(A(-z) = A(z)\). Every power in \(B\) has an odd exponent, so \(B(-z) = -B(z)\). 4. \(B(2) = 6\) and \(B(-2) = -6\). Adding the same constant \(c\) gives \(6 + c\) and \(-6 + c\), whose difference remains \(12\), so they cannot become equal.

Answer

a) \(A(3) = A(-3) = 36\); \(B(3) = 24\), \(B(-3) = -24\) b) \(A(-z) = A(z)\) because its exponents are even; \(B(-z) = -B(z)\) because its exponents are odd. c) \(B(2) = 6\), \(B(-2) = -6\). No; adding the same constant does not change their difference.
5230308
Find the expression or exponent that belongs in each box. a) \(a^7 \cdot a^{\Box} = a^{12}\) b) \(x^n \cdot x^4 = x^{n+\Box}\) c) \(y^3 \cdot \Box = -y^8\) d) \(c^{k+2} \cdot c^{k-1} = c^{\Box}\)

Hints

- Add exponents for powers with the same base. - Write a simple equation for the missing exponent. - In part c), account for both the exponent and the negative sign.

Solution

1. a) Since \(7 + \Box = 12\), the exponent is \(5\). 2. b) Since the exponent on the product is \(n + 4\), the box is \(4\). 3. c) The missing factor must supply a negative sign and five more factors of \(y\), so it is \(-y^5\). 4. d) Add the exponent expressions: \((k + 2) + (k - 1) = 2k + 1\).

Answer

a) \(5\) b) \(4\) c) \(-y^5\) d) \(2k + 1\)
5230328
Complete each equation or expression. a) \(3x^4 \cdot \Box = 12x^9\) b) \(\Box \cdot (-5a^2) = 20a^3\) c) Simplify \(y^k \cdot y^5\). d) Paul says, “When multiplying powers with the same base, multiply the exponents.” Test his claim using \(2^3 \cdot 2^2\), and correct it if necessary.

Hints

- Divide coefficients to find a missing factor. - Find the exponent needed to reach the exponent in the product. - Expand the powers in part d) to test the claimed rule.

Solution

1. a) The missing coefficient is \(12 \div 3 = 4\), and the missing exponent is \(9 - 4 = 5\), so the factor is \(4x^5\). 2. b) The missing coefficient is \(20 \div (-5) = -4\), and the missing exponent is \(3 - 2 = 1\), so the factor is \(-4a\). 3. c) \(y^k \cdot y^5 = y^{k+5}\). 4. d) \(2^3 \cdot 2^2 = 8 \cdot 4 = 32 = 2^5\), not \(2^6\). The exponents are added, not multiplied.

Answer

a) \(4x^5\) b) \(-4a\) c) \(y^{k+5}\) d) Paul is incorrect; \(2^3 \cdot 2^2 = 2^{3+2} = 2^5 = 32\).
5230348
Complete each task. 1) Simplify \(\left(-\frac{4}{7}x^5y^n\right)\left(\frac{14}{8}x^2y^3\right)\). 2) Find the missing factor: \(\Box \cdot (-3a^2b^4) = 12a^5b^7\). 3) Multiply \((-u^3v^2)\) and \((1.2u^kv)\).

Hints

- Simplify fractional coefficients before multiplying. - Use division to find a missing factor. - Add variable exponents formally, even when they contain letters.

Solution

1. The coefficient product is \(-\frac{4}{7} \cdot \frac{14}{8} = -1\). Add exponents to get \(-x^7y^{n+3}\). 2. Divide coefficients and subtract exponents: \(12 \div (-3) = -4\), \(5 - 2 = 3\), and \(7 - 4 = 3\). The factor is \(-4a^3b^3\). 3. Multiply coefficients and add exponents: \((-1) \cdot 1.2u^{3+k}v^{2+1} = -1.2u^{k+3}v^3\).

Answer

1) \(-x^7y^{n+3}\) 2) \(-4a^3b^3\) 3) \(-1.2u^{k+3}v^3\)
5230368
Find the missing factor and explain how you determined its coefficient and exponent. \((2b^n)(\Box) = -10b^{n+3}\)

Hints

- Determine what multiplies \(2\) to produce \(-10\). - Determine what exponent must be added to \(n\) to produce \(n + 3\). - Substitute your factor to check the equation.

Solution

1. Divide the target coefficient by the known coefficient: \(-10 \div 2 = -5\). 2. If the missing exponent is \(r\), then \(n + r = n + 3\), so \(r = 3\). 3. The missing factor is \(-5b^3\).

Answer

\(-5b^3\)
5230378
Check each result. Identify correct work and correct every error. 1) \((4a^2b)(3ab^3) = 12a^2b^3\) 2) \((-5x^3y^2)(-2xy) = 10x^4y^3\) 3) \(\left(\frac{2}{3}m^2n^4\right)(6m^3n) = 4m^6n^4\)

Hints

- A variable without a written exponent has exponent \(1\). - Add exponents when multiplying powers with the same base. - Check the coefficient and each variable separately.

Solution

1. The coefficients give \(12\), but the exponents must be added: \(a^{2+1}b^{1+3} = a^3b^4\). The correct result is \(12a^3b^4\). 2. The coefficients give \(10\), and the variable powers give \(x^4y^3\). This result is correct. 3. The coefficient is \(\frac{2}{3} \cdot 6 = 4\), and the variable powers give \(m^{2+3}n^{4+1} = m^5n^5\). The correct result is \(4m^5n^5\).

Answer

1) Incorrect; \(12a^3b^4\) 2) Correct 3) Incorrect; \(4m^5n^5\)
5230388
A rectangular prism has edge lengths \(a = 2x^2y\), \(b = 1.5xy^2\), and \(c = 4x^3\), where \(x > 0\) and \(y > 0\). a) Write and simplify an expression for its volume \(V\). b) What is the new volume if only edge \(c\) is doubled? c) What is the new volume if all three edge lengths are doubled? State the factor by which the original volume changes.

Hints

- Use the volume formula \(V = abc\). - Group coefficients and like variable bases. - Count how many factors of \(2\) enter the volume when edges are doubled.

Solution

1. a) \(V = abc = (2x^2y)(1.5xy^2)(4x^3)\). Multiply coefficients and add exponents: \(V = 12x^6y^3\). 2. b) Doubling one edge doubles the volume, so the new volume is \(24x^6y^3\). 3. c) Doubling all three edges multiplies the volume by \(2^3 = 8\), so the new volume is \(96x^6y^3\).

Answer

a) \(12x^6y^3\) b) \(24x^6y^3\) c) \(96x^6y^3\); the volume is multiplied by \(8\).
5230408
A student simplified the expressions below. Determine which results are correct. Correct each incorrect result and briefly identify the error. a) \((2z^4)^3=6z^{12}\) b) \((-5k^2)^2=25k^4\) c) \((a^3)^2=a^5\) d) \(\left(\frac{2}{3}m\right)^2=\frac{4}{9}m^2\)

Hints

- Raise coefficients as well as variable factors to the outside power. - Multiply exponents when raising a power to a power. - When squaring a fraction, square both numerator and denominator.

Solution

1. a) Incorrect. The coefficient must be cubed: \((2z^4)^3 = 2^3z^{12} = 8z^{12}\). 2. b) Correct: \((-5k^2)^2 = 25k^4\). 3. c) Incorrect. Exponents are multiplied when raising a power to a power: \((a^3)^2 = a^6\). 4. d) Correct: \(\left(\frac{2}{3}m\right)^2 = \frac{4}{9}m^2\).

Answer

a) Incorrect; \(8z^{12}\). The coefficient was multiplied by the exponent instead of raised to the power. b) Correct c) Incorrect; \(a^6\). The exponents were added instead of multiplied. d) Correct
5230418
Simplify each product. 1) \((1.2a^nb^k)(-5a^{n+1}b^{3k})\) 2) \(\left(-\frac{2}{5}x^{m-1}y^2\right)\left(\frac{15}{4}x^3y^{m+1}\right)\)

Hints

- Add exponents when multiplying powers with the same base. - Apply sign rules when multiplying coefficients. - Treat exponent expressions as grouped quantities before simplifying.

Solution

1. Multiply coefficients: \(1.2 \cdot (-5) = -6\). Add exponents: \(a^{n+(n+1)} = a^{2n+1}\) and \(b^{k+3k} = b^{4k}\). The result is \(-6a^{2n+1}b^{4k}\). 2. The coefficient product is \(-\frac{2}{5} \cdot \frac{15}{4} = -\frac{3}{2}\). Add exponents: \(x^{(m-1)+3} = x^{m+2}\) and \(y^{2+(m+1)} = y^{m+3}\). The result is \(-\frac{3}{2}x^{m+2}y^{m+3}\).

Answer

1) \(-6a^{2n+1}b^{4k}\) 2) \(-\frac{3}{2}x^{m+2}y^{m+3}\)
5230428
Find the missing coefficient \(\Box\) and the value of \(n\) that make the equation true. \((4a^kb^2)(\Box a^{k+1}b^n) = -12a^{2k+1}b^7\)

Hints

- Compare the coefficient and each variable base separately. - Solve \(4 \cdot \Box = -12\). - Write an equation for the exponents on \(b\).

Solution

1. Compare coefficients: \(4 \cdot \Box = -12\), so \(\Box = -3\). 2. The powers of \(a\) already match because \(a^k \cdot a^{k+1} = a^{2k+1}\). 3. Compare the powers of \(b\): \(2 + n = 7\), so \(n = 5\).

Answer

\(\Box = -3\) and \(n = 5\)
5230438
Simplify each expression. a) \((5a^2)^3 \cdot 2a^5\) b) \((-2x^3)^4 \cdot (-3x^2)\)

Hints

- Raise each factor inside parentheses to the outside power. - Multiply exponents when raising a power to a power. - Add exponents when multiplying powers with the same base.

Solution

1. a) \((5a^2)^3 = 125a^6\). Then \(125a^6 \cdot 2a^5 = 250a^{11}\). 2. b) \((-2x^3)^4 = 16x^{12}\). Then \(16x^{12} \cdot (-3x^2) = -48x^{14}\).

Answer

a) \(250a^{11}\) b) \(-48x^{14}\)
5230448
Simplify \((2xy^3)^3 \cdot (-0.5x^2y)^4\).

Hints

- Simplify each powered monomial separately. - An even power makes the negative coefficient positive. - Multiply coefficients and add exponents at the end.

Solution

1. \((2xy^3)^3 = 2^3x^3y^9 = 8x^3y^9\). 2. \((-0.5x^2y)^4 = (-0.5)^4x^8y^4 = \frac{1}{16}x^8y^4\). 3. Multiply: \(8 \cdot \frac{1}{16} = \frac{1}{2}\), \(x^{3+8} = x^{11}\), and \(y^{9+4} = y^{13}\). 4. The result is \(\frac{1}{2}x^{11}y^{13}\).

Answer

\(\frac{1}{2}x^{11}y^{13}\)
5230468
Let \(A = (-2a^3)^4\) and \(B = (-4a^6)^2\). a) Simplify both expressions and compare the results. b) Explain without calculating why Expression A must have a positive coefficient. c) Change only the outside exponent in Expression A so that the simplified result has a negative coefficient. Give one possible expression and its result.

Hints

- Apply the power to the coefficient and the variable factor. - Recall the sign of a negative number raised to an even power. - Choose an odd outside exponent in part c).

Solution

1. a) \(A = (-2)^4a^{12} = 16a^{12}\), and \(B = (-4)^2a^{12} = 16a^{12}\). The expressions are equivalent. 2. b) The outside exponent \(4\) is even, so the negative coefficient becomes positive. 3. c) Any odd outside exponent works. For example, \((-2a^3)^3 = -8a^9\).

Answer

a) \(A = B = 16a^{12}\) b) The coefficient is positive because the outside exponent is even. c) One example is \((-2a^3)^3 = -8a^9\).
5230498
Simplify \((-3a^kb^2)^3 \cdot (2a^2b^n)^2\).

Hints

- Simplify each powered monomial first. - Determine the sign from the parity of the outside exponent. - Add exponents when multiplying powers with the same base.

Solution

1. \((-3a^kb^2)^3 = -27a^{3k}b^6\). 2. \((2a^2b^n)^2 = 4a^4b^{2n}\). 3. Multiply the results: \((-27) \cdot 4 = -108\), \(a^{3k}a^4 = a^{3k+4}\), and \(b^6b^{2n} = b^{2n+6}\). 4. The simplified expression is \(-108a^{3k+4}b^{2n+6}\).

Answer

\(-108a^{3k+4}b^{2n+6}\)
5230508
A student claims, “It makes no difference whether I square \(-x\) and then cube the result, or cube \(-x\) and then square the result.” Test the claim by simplifying \(T_1 = ((-x)^2)^3\) and \(T_2 = ((-x)^3)^2\).

Hints

- Work from the innermost power outward. - Track the sign after an even or odd power. - Compare the final exponents and signs.

Solution

1. \(T_1 = (x^2)^3 = x^6\). 2. \(T_2 = (-x^3)^2 = x^6\). 3. Both expressions simplify to \(x^6\), so the claim is correct.

Answer

The claim is true because both expressions simplify to \(x^6\).
5238308
Let \(T = \frac{x^n}{y}\), where \(n\) is a positive integer and \(y \ne 0\). a) Find \(n\) so that doubling both \(x\) and \(y\) multiplies the value of \(T\) by \(4\). b) Verify the claim: “If both variables in \(\frac{x + y}{xy}\) are doubled, the value of the expression is divided by \(2\).” Show the algebra.

Hints

- Substitute \(2x\) and \(2y\) using parentheses. - Factor out the original expression after simplifying. - Which power of \(2\) equals \(4\)? - Compare the multiplier with the stated change.

Solution

1. After doubling both variables, \(\frac{(2x)^n}{2y} = \frac{2^n x^n}{2y} = 2^{n - 1}\frac{x^n}{y}\). 2. For the value to be multiplied by \(4\), require \(2^{n - 1} = 4 = 2^2\). 3. Therefore, \(n - 1 = 2\), so \(n = 3\). 4. For part b, doubling both variables gives \(\frac{2x + 2y}{(2x)(2y)} = \frac{2(x + y)}{4xy} = \frac{1}{2}\frac{x + y}{xy}\). 5. The transformed expression is one-half of the original, so the claim is true.

Answer

a) \(n = 3\). b) The claim is true because the transformed expression is \(\frac{1}{2}\) times the original expression.
5240908
Is \(a^2 \ge a\) true for every rational number \(a\)? Explain and give a counterexample if the statement is false.

Hints

- Test several types of rational numbers, including one between \(0\) and \(1\). - Squaring a positive number between \(0\) and \(1\) makes it smaller.

Solution

1. Test a rational number between \(0\) and \(1\), such as \(a = 0.5\). 2. Then \(a^2 = 0.25\), and \(0.25 \ge 0.5\) is false. 3. Therefore, the inequality is not true for every rational number.

Answer

No. For \(a = 0.5\), \(a^2 = 0.25 < 0.5\).
5245338
Evaluate each expression, paying close attention to signs. 1) \((-4)^2\) and \(-4^2\) 2) \((-1)^{101}\) and \((-1)^{202}\) 3) \((-2)^5 + (-3)^3\) 4) \(-(-1)^{2n}\) for any natural number \(n\)

Hints

- Determine whether the negative sign is inside the base. - Use even and odd exponents to determine signs. - Evaluate powers before addition or subtraction.

Solution

1. \((-4)^2 = 16\), while \(-4^2 = -16\). 2. Since \(101\) is odd, \((-1)^{101} = -1\). Since \(202\) is even, \((-1)^{202} = 1\). 3. \((-2)^5 + (-3)^3 = -32 - 27 = -59\). 4. Since \(2n\) is even, \((-1)^{2n} = 1\), so \(-(-1)^{2n} = -1\).

Answer

1) \(16\) and \(-16\) 2) \(-1\) and \(1\) 3) \(-59\) 4) \(-1\)
5245348
Evaluate each expression. 1) \(\left(-\frac{2}{3}\right)^3\) 2) \(0.2^2 - (-0.1)^3\) 3) \((-1)^7 \cdot \left(\frac{1}{2}\right)^2 + 0.75\) 4) Evaluate \(T(x, y) = x^4 - y^3\) for \(x = -2\) and \(y = -2\).

Hints

- Apply powers before multiplication, addition, or subtraction. - Raise both numerator and denominator of a fraction to the power. - Use parentheses when substituting negative values.

Solution

1. \(\left(-\frac{2}{3}\right)^3 = -\frac{8}{27}\). 2. \(0.2^2 - (-0.1)^3 = 0.04 - (-0.001) = 0.041\). 3. \((-1)^7 \cdot \left(\frac{1}{2}\right)^2 + 0.75 = -0.25 + 0.75 = 0.5\). 4. \((-2)^4 - (-2)^3 = 16 - (-8) = 24\).

Answer

1) \(-\frac{8}{27}\) 2) \(0.041\) 3) \(0.5\) 4) \(24\)
5245478
Simplify each expression as much as possible using properties of exponents. Assume \(k, n, p\) are positive integers and all variable values make the expressions defined. 1. \((-3a^2b^k)^4\) 2. \(\left(\frac{2x^n}{y^3}\right)^3\) 3. \(\frac{(m^4q^2)^p}{m^{3p}}\)

Hints

- What happens to the exponents when a power is raised to another power? - How does an even outer exponent affect a negative factor? - When dividing powers with the same base, subtract the exponents. - Apply the outer exponent to every factor inside the parentheses.

Solution

1. Apply the exponent to every factor: \((-3a^2b^k)^4 = (-3)^4(a^2)^4(b^k)^4 = 81a^8b^{4k}\). 2. Raise the numerator and denominator to the third power: \(\left(\frac{2x^n}{y^3}\right)^3 = \frac{2^3(x^n)^3}{(y^3)^3} = \frac{8x^{3n}}{y^9}\). 3. Simplify the numerator, then divide powers with the same base: \(\frac{(m^4q^2)^p}{m^{3p}} = \frac{m^{4p}q^{2p}}{m^{3p}} = m^{4p-3p}q^{2p} = m^pq^{2p}\).

Answer

1. \(81a^8b^{4k}\) 2. \(\frac{8x^{3n}}{y^9}\) 3. \(m^pq^{2p}\)
5245518
Simplify using exponent properties. Write the answer without negative exponents. Assume \(x\ne0\), \(y\ne0\), and \(z\ne0\). \(\frac{(x^2y^{-3})^2\cdot(x^4z^2)^3}{(x^2yz)^4}\cdot\frac{y^2}{z^{-1}}\)

Hints

- Expand every power of a product first. - Subtract exponents when dividing like bases. - Move factors with negative exponents across the fraction bar.

Solution

1. Expand the powers: \((x^2y^{-3})^2=x^4y^{-6}\), \((x^4z^2)^3=x^{12}z^6\), and \((x^2yz)^4=x^8y^4z^4\). 2. The first fraction simplifies to \(x^{16-8}y^{-6-4}z^{6-4}=x^8y^{-10}z^2\). 3. Since \(\frac{y^2}{z^{-1}}=y^2z\), the full product is \(x^8y^{-8}z^3=\frac{x^8z^3}{y^8}\).

Answer

\(\frac{x^8z^3}{y^8}\)
5245528
For \(a\ne0\), \(b\ne0\), and \(c\ne0\), simplify \(\left(\frac{a^3(b^2c^{-1})^2}{(a^{-1}b)^3}\right)^{-2}\div\frac{c^4}{a^{10}b^2}\). Show that the final result depends only on \(a\).

Hints

- Simplify inside the parentheses before applying the outside exponent. - Dividing by a fraction means multiplying by its reciprocal. - A nonzero factor with exponent \(0\) equals \(1\).

Solution

1. Inside the parentheses, the numerator is \(a^3b^4c^{-2}\) and the denominator is \(a^{-3}b^3\). Thus the fraction is \(a^6bc^{-2}\). 2. Apply the exponent \(-2\): \((a^6bc^{-2})^{-2}=a^{-12}b^{-2}c^4\). 3. Divide by the second fraction by multiplying by its reciprocal: \(a^{-12}b^{-2}c^4\cdot\frac{a^{10}b^2}{c^4}=a^{-2}=\frac{1}{a^2}\). 4. The factors involving \(b\) and \(c\) have exponent \(0\), so the result depends only on \(a\).

Answer

\(\frac{1}{a^2}\)
5245538
Simplify the expression as much as possible for \(x, y, z \ne 0\): \(\frac{(4x^3y)^2(3z^2)^3}{12x^4(yz)^2}\)

Hints

- Simplify the powers in the numerator and denominator separately. - Apply the outer exponent to every factor in a product. - When dividing powers with the same base, subtract the exponents. - Treat the numerical coefficients and variable factors separately.

Solution

1. Expand the powers in the numerator: \((4x^3y)^2 = 16x^6y^2\) and \((3z^2)^3 = 27z^6\). 2. Multiply the numerator: \(16 \cdot 27x^6y^2z^6 = 432x^6y^2z^6\). 3. Expand the denominator: \(12x^4(yz)^2 = 12x^4y^2z^2\). 4. Divide coefficients and subtract exponents of like bases: \(\frac{432}{12}x^{6-4}y^{2-2}z^{6-2} = 36x^2z^4\).

Answer

\(36x^2z^4\)
5245548
For \(a\ne0\), \(b\ne0\), and \(c\ne0\), simplify and write the result as a product of powers: \(\frac{(5a^2b^{-1})^2\cdot(2a^{-2}c)^3}{(10a^{-1}b^{-2}c^2)^2}\).

Hints

- Expand each power of a product first. - Combine the numerator before dividing. - Subtract negative exponents carefully.

Solution

1. Expand the numerator: \((5a^2b^{-1})^2=25a^4b^{-2}\) and \((2a^{-2}c)^3=8a^{-6}c^3\). Their product is \(200a^{-2}b^{-2}c^3\). 2. Expand the denominator: \((10a^{-1}b^{-2}c^2)^2=100a^{-2}b^{-4}c^4\). 3. Divide coefficients and subtract exponents: \(2a^0b^2c^{-1}=2b^2c^{-1}\).

Answer

\(2b^2c^{-1}\)
5245558
Simplify the expression as much as possible using properties of exponents: \([(-2x)^2]^3 - (-4x^3)^2 + [-(2x)^3]^2 - 2(-2x^2)^3\)

Hints

- Track the sign carefully when a negative base is raised to an even or odd power. - Simplify the innermost powers first. - Use \((a^m)^n = a^{mn}\). - After simplifying, check whether all terms contain the same power of \(x\).

Solution

1. Simplify the first term: \([(-2x)^2]^3 = (4x^2)^3 = 64x^6\). 2. Simplify the second term: \((-4x^3)^2 = 16x^6\). 3. Simplify the third term: \([-(2x)^3]^2 = (-8x^3)^2 = 64x^6\). 4. Simplify the factor in the fourth term: \(2(-2x^2)^3 = 2(-8x^6) = -16x^6\). 5. Combine like terms, including the subtraction before the fourth term: \(64x^6 - 16x^6 + 64x^6 - (-16x^6) = 128x^6\).

Answer

\(128x^6\)
5245568
For \(a \ne 0\), let \(A = \frac{[(-a)^2(-2a)^2]^2}{(-2a^2)^3}\). a) Simplify \(A\) as much as possible. b) Evaluate the expression when \(a = -2\).

Hints

- Simplify the numerator and denominator separately before dividing. - When dividing powers with the same base, subtract the exponents. - Use parentheses when substituting a negative number for \(a\).

Solution

1. Simplify inside the brackets in the numerator: \((-a)^2 = a^2\) and \((-2a)^2 = 4a^2\), so their product is \(4a^4\). 2. Square the product: \((4a^4)^2 = 16a^8\). 3. Simplify the denominator: \((-2a^2)^3 = (-2)^3(a^2)^3 = -8a^6\). 4. Divide: \(\frac{16a^8}{-8a^6} = -2a^{8-6} = -2a^2\). 5. Substitute \(a = -2\): \(-2(-2)^2 = -2 \cdot 4 = -8\).

Answer

a) \(-2a^2\) b) \(-8\)
5245598
Simplify the expression as much as possible. Assume \(m\) and \(n\) are positive integers and \(a, b \ne 0\): \(\frac{(2a^n b^{2m})^5}{8a^{3n}(b^m)^{10}}\)

Hints

- Apply an exponent outside parentheses to every factor inside. - Use the power of a power property. - When dividing powers with the same base, subtract the exponents. - Recall the value of a nonzero base raised to the zero power.

Solution

1. Apply the exponent to each factor in the numerator: \((2a^n b^{2m})^5 = 2^5(a^n)^5(b^{2m})^5 = 32a^{5n}b^{10m}\). 2. Simplify the power in the denominator: \((b^m)^{10} = b^{10m}\). 3. Divide: \(\frac{32a^{5n}b^{10m}}{8a^{3n}b^{10m}} = 4a^{5n-3n}b^{10m-10m}\). 4. Since \(b^0 = 1\), the expression simplifies to \(4a^{2n}\).

Answer

\(4a^{2n}\)
5245608
Simplify the expression as much as possible using properties of exponents. Assume \(k\) and \(n\) are positive integers, \(x+y \ne 0\), and \(z \ne 0\): \(\frac{[5(x+y)^{2k}z^n]^3}{[25(x+y)^{3k}z^{2n}]^2} \cdot \frac{125z^n}{(x+y)^k}\)

Hints

- Apply each outer exponent to every factor inside its brackets. - Treat \(x+y\) as a single base. - Simplify the first fraction before multiplying by the second fraction. - What happens when exponents of the same base add to zero?

Solution

1. Expand the powers in the first numerator: \([5(x+y)^{2k}z^n]^3 = 125(x+y)^{6k}z^{3n}\). 2. Expand the powers in the first denominator: \([25(x+y)^{3k}z^{2n}]^2 = 625(x+y)^{6k}z^{4n}\). 3. Simplify the first fraction: \(\frac{125(x+y)^{6k}z^{3n}}{625(x+y)^{6k}z^{4n}} = \frac{1}{5}z^{-n}\). 4. Multiply by the second fraction: \(\frac{1}{5}z^{-n} \cdot \frac{125z^n}{(x+y)^k} = \frac{25z^0}{(x+y)^k}\). 5. Since \(z^0 = 1\), the simplified expression is \(\frac{25}{(x+y)^k}\).

Answer

\(\frac{25}{(x+y)^k}\)
5245738
Evaluate using exponent properties. a) \((1.5)^{-2}+\left(\frac{1}{3}\right)^{-1}\cdot4^{-1}\) b) \(\frac{3^{-1}+\left(\frac{2}{3}\right)^{-2}}{2^2-7\cdot2^{-1}}\)

Hints

- Rewrite decimals as fractions. - Evaluate the numerator and denominator separately. - Dividing by a fraction means multiplying by its reciprocal.

Solution

1. For part a, \((1.5)^{-2}=\left(\frac{3}{2}\right)^{-2}=\frac{4}{9}\), \(\left(\frac{1}{3}\right)^{-1}=3\), and \(4^{-1}=\frac{1}{4}\). Thus \(\frac{4}{9}+\frac{3}{4}=\frac{43}{36}\). 2. For part b, the numerator is \(\frac{1}{3}+\frac{9}{4}=\frac{31}{12}\). The denominator is \(4-\frac{7}{2}=\frac{1}{2}\). Therefore, \(\frac{31}{12}\div\frac{1}{2}=\frac{31}{6}\).

Answer

a) \(\frac{43}{36}\) b) \(\frac{31}{6}\)
5245748
Evaluate and give the result as a fraction in lowest terms or as a decimal: \(\frac{2^3\cdot2^{-5}+3^{-2}}{\left(\frac{1}{3}\right)^2-(-2)^{-2}}\).

Hints

- Combine powers with the same base first. - Evaluate the main numerator and denominator separately. - Track the sign of the denominator carefully.

Solution

1. The numerator is \(2^{-2}+\frac{1}{9}=\frac{1}{4}+\frac{1}{9}=\frac{13}{36}\). 2. The denominator is \(\frac{1}{9}-\frac{1}{4}=-\frac{5}{36}\). 3. Divide: \(\frac{13}{36}\div\left(-\frac{5}{36}\right)=-\frac{13}{5}=-2.6\).

Answer

\(-\frac{13}{5}\), or \(-2.6\)
5245848
Rewrite each expression without a fraction bar by using negative exponents. Preserve the grouping. 1) \(\frac{a^3b^2}{c^4}\), where \(c\ne0\) 2) \(\frac{1}{x^2+y^2}\), where \(x^2+y^2\ne0\) 3) \(\frac{1}{r^3}-\frac{1}{s^3}\cdot\frac{1}{t^2}\), where \(r,s,t\ne0\) 4) \(\frac{1}{\frac{1}{u^2}-\frac{1}{v^2}}\), where \(u\ne0\), \(v\ne0\), and \(u\ne\pm v\)

Hints

- Treat a sum or difference in a denominator as one grouped base. - Change the sign of an exponent when moving a factor across the fraction bar. - Preserve multiplication before subtraction in part 3).

Solution

1. Move \(c^4\) to the numerator with exponent \(-4\): \(a^3b^2c^{-4}\). 2. Treat the entire sum as the base: \((x^2+y^2)^{-1}\). 3. Rewrite each reciprocal while preserving the order of operations: \(r^{-3}-s^{-3}t^{-2}\). 4. Rewrite the inner reciprocals first, then invert the entire denominator: \((u^{-2}-v^{-2})^{-1}\).

Answer

1) \(a^3b^2c^{-4}\) 2) \((x^2+y^2)^{-1}\) 3) \(r^{-3}-s^{-3}t^{-2}\) 4) \((u^{-2}-v^{-2})^{-1}\)
5245908
Assume every variable appearing in a denominator or with a negative exponent is nonzero. Simplify each expression and write the result as a product with no fraction bar. 1) \(\frac{4x^5}{2x^7y^2}\) 2) \(\frac{(2a)^{-2}b^3}{a^2c}\) 3) \(\frac{0.25u^2v^{-1}}{w^2z^{-2}}\)

Hints

- Simplify coefficients before removing the fraction bar. - Apply a negative exponent to every factor inside parentheses. - Change exponent signs when moving denominator factors.

Solution

1. Divide coefficients and subtract exponents: \(2x^{-2}y^{-2}\). 2. Since \((2a)^{-2}=0.25a^{-2}\), dividing by \(a^2c\) gives \(0.25a^{-4}b^3c^{-1}\). 3. Move the denominator factors to the numerator: \(0.25u^2v^{-1}w^{-2}z^2\).

Answer

1) \(2x^{-2}y^{-2}\) 2) \(0.25a^{-4}b^3c^{-1}\) 3) \(0.25u^2v^{-1}w^{-2}z^2\)
5245968
Let \(T_1=\frac{2}{(x+y)^{-3}}\) and \(T_2=\frac{1}{0.5(x+y)^{-3}}\). Determine whether the expressions are equivalent for all \(x\ne-y\). Justify your answer by rewriting both without fraction bars.

Hints

- Move the negative power from the denominator to the numerator. - Find the reciprocal of \(0.5\). - Compare the two rewritten expressions.

Solution

1. Move \((x+y)^{-3}\) from the denominator: \(T_1=2(x+y)^3\). 2. Since the reciprocal of \(0.5\) is \(2\), \(T_2=2(x+y)^3\). 3. Both expressions simplify to the same result, so they are equivalent for every allowed pair.

Answer

Yes. Both expressions simplify to \(2(x+y)^3\) for \(x\ne-y\).
5245978
Rewrite each expression with no fraction bar. Use negative-exponent properties and simplify as far as possible. 1) \(\frac{12}{(x+y)^{-2}}\) 2) \(\frac{5ab}{2(a-b)^{-3}}\) 3) \(\frac{3^{-1}(m+n)}{6^{-1}p^{-2}(m-n)^{-1}}\)

Hints

- Change the sign of a denominator exponent when moving the factor to the numerator. - Simplify numerical coefficients separately. - Look for a difference-of-squares product in part 3).

Solution

1. Move \((x+y)^{-2}\) from the denominator: \(12(x+y)^2\). 2. Since \(5\div2=2.5\), the result is \(2.5ab(a-b)^3\). 3. The coefficient is \(3^{-1}\div6^{-1}=2\). Moving the remaining denominator factors gives \(2p^2(m+n)(m-n)\). 4. Use the difference of squares: \(2p^2(m+n)(m-n)=2p^2(m^2-n^2)\). 5. The original restrictions are \(x+y\ne0\), \(a-b\ne0\), \(p\ne0\), and \(m-n\ne0\).

Answer

1) \(12(x+y)^2\), where \(x+y\ne0\) 2) \(2.5ab(a-b)^3\), where \(a\ne b\) 3) \(2p^2(m^2-n^2)\), where \(p\ne0\) and \(m\ne n\)
5245988
Let \(T=\frac{0.2(a+b)}{5^{-1}c^{-2}(a-b)^{-2}}\). a) Simplify the expression and write it without a fraction bar. b) Evaluate the expression when \(a=7\), \(b=3\), and \(c=0.1\).

Hints

- Rewrite \(5^{-1}\) as a decimal or fraction. - Move negative powers from the denominator to the numerator. - Substitute only after simplifying.

Solution

1. Since \(5^{-1}=0.2\), the numerical factors cancel. 2. Move the negative powers from the denominator: \(T=c^2(a+b)(a-b)^2\). 3. The original expression requires \(c\ne0\) and \(a\ne b\). 4. Substitute the given values: \(T=(0.1)^2(7+3)(7-3)^2=0.01\cdot10\cdot16=1.6\).

Answer

a) \(T=c^2(a+b)(a-b)^2\), where \(c\ne0\) and \(a\ne b\) b) \(1.6\)
5246068
Assume \(x\ne0\) and \(y\ne0\). Two students simplify \(S=\frac{2^{-3}x^2y^{-2}}{8^{-1}x^{-1}y}\). Leon claims the result is \(x^3y^{-3}\). Sophie claims the result is \(\frac{x^3}{y^3}\). Check both claims and determine whether the results are equivalent.

Hints

- Simplify the numerical coefficient first. - Subtract exponents for each variable separately. - Rewrite the negative exponent as a reciprocal to compare the answers.

Solution

1. The numerical quotient is \(2^{-3}\div8^{-1}=\frac{1}{8}\div\frac{1}{8}=1\). 2. For \(x\), \(x^2\div x^{-1}=x^{2-(-1)}=x^3\). 3. For \(y\), \(y^{-2}\div y=y^{-3}\). 4. Thus \(S=x^3y^{-3}\), so Leon is correct. 5. Since \(y^{-3}=\frac{1}{y^3}\), \(x^3y^{-3}=\frac{x^3}{y^3}\), so Sophie is also correct.

Answer

Both students are correct because \(x^3y^{-3}=\frac{x^3}{y^3}\).
5246088
Use exponent properties to simplify. In both parts, let \(k,n\in\mathbb{Z}\), and assume all expressions are defined. a) \(\frac{15a^{2k}b^{k-1}}{3a^kb^{2k}}\) b) \(\left(\frac{1}{2}x^{-n}y^2\right)^{-2}\cdot4x^{-2n}\)

Hints

- Treat variable expressions in exponents like numerical expressions. - Apply an outside exponent to every factor. - Subtract negative exponents carefully.

Solution

1. Divide coefficients and subtract exponents: \(5a^{2k-k}b^{(k-1)-2k}=5a^kb^{-k-1}=\frac{5a^k}{b^{k+1}}\). 2. Expand the power: \(\left(\frac{1}{2}x^{-n}y^2\right)^{-2}=4x^{2n}y^{-4}\). Multiplying by \(4x^{-2n}\) gives \(16x^0y^{-4}=\frac{16}{y^4}\).

Answer

a) \(\frac{5a^k}{b^{k+1}}\) b) \(\frac{16}{y^4}\)
5246108
Assume \(x\ne0,-2\). a) Show that \(\frac{1}{4x^2}\) and \(0.25x^{-2}\) are equivalent. b) Rewrite \(T=\frac{3}{5(x+2)^2}\) with no fraction bar. c) Evaluate \(T\) when \(x=3\).

Hints

- Separate the numerical coefficient from the variable power. - Treat the entire binomial \(x+2\) as the base. - Evaluate the parentheses before applying the negative exponent.

Solution

1. For a), \(\frac{1}{4x^2}=\frac{1}{4}\cdot\frac{1}{x^2}=0.25x^{-2}\). 2. For b), \(\frac{3}{5}=0.6\), so \(T=0.6(x+2)^{-2}\). 3. For c), \(T=0.6(3+2)^{-2}=0.6\cdot5^{-2}=0.6\cdot0.04=0.024\).

Answer

a) \(\frac{1}{4x^2}=0.25x^{-2}\) b) \(0.6(x+2)^{-2}\) c) \(0.024\)
5246158
Rewrite each expression using only positive exponents. Simplify as far as possible. 1) \(\frac{6a^{-3}}{b^{-2}}\) 2) \(\frac{(x+y)^{-1}}{2^{-3}z^{-4}}\) 3) \(\frac{p^{-2}q^3}{r^{-1}(p-q)^{-2}}\)

Hints

- Move a negative power across the fraction bar to make its exponent positive. - Treat a binomial in parentheses as one base. - Preserve all restrictions from the original expression.

Solution

1. Move the negative powers across the fraction bar: \(\frac{6b^2}{a^3}\). 2. Move \(2^{-3}\) and \(z^{-4}\) to the numerator: \(\frac{2^3z^4}{x+y}=\frac{8z^4}{x+y}\). 3. Move the negative powers: \(\frac{q^3r(p-q)^2}{p^2}\). 4. The original restrictions are \(a,b\ne0\); \(x+y\ne0\) and \(z\ne0\); and \(p\ne0\), \(r\ne0\), and \(p-q\ne0\).

Answer

1) \(\frac{6b^2}{a^3}\), where \(a,b\ne0\) 2) \(\frac{8z^4}{x+y}\), where \(x+y\ne0\) and \(z\ne0\) 3) \(\frac{q^3r(p-q)^2}{p^2}\), where \(p\ne0\), \(r\ne0\), and \(p\ne q\)
5246168
Two expressions are equivalent if they have the same value for every allowed input. Determine whether \(A=\frac{(2x)^{-3}}{y^{-2}}\) and \(B=\frac{y^2}{8x^3}\) are equivalent for \(x\ne0\) and \(y\ne0\). Justify your answer by rewriting \(A\).

Hints

- Rewrite the numerator and denominator without negative exponents. - Apply the exponent to both factors in \(2x\). - Divide by multiplying by the reciprocal.

Solution

1. Rewrite the numerator: \((2x)^{-3}=\frac{1}{(2x)^3}=\frac{1}{8x^3}\). 2. Rewrite the denominator: \(y^{-2}=\frac{1}{y^2}\). 3. Simplify the complex fraction: \(A=\frac{1}{8x^3}\div\frac{1}{y^2}=\frac{1}{8x^3}\cdot y^2=\frac{y^2}{8x^3}\). 4. This is exactly \(B\), so the expressions are equivalent.

Answer

Yes. Both expressions equal \(\frac{y^2}{8x^3}\) for \(x\ne0\) and \(y\ne0\).
5246178
Expand and simplify using exponent properties. Assume \(x\ne0\), \(m\ne0\), and \(n\ne0\). a) \((2x^2+3x^{-1})(x-2x^{-2})\) b) \((3m^2-2n^{-1})(m^{-2}+n)\)

Hints

- Multiply every term in the first factor by every term in the second. - Add exponents when multiplying like bases. - Replace every nonzero base to the zero power with \(1\).

Solution

1. Expand part a: \(2x^3-4x^0+3x^0-6x^{-3}=2x^3-1-6x^{-3}\). 2. Expand part b: \(3m^0+3m^2n-2m^{-2}n^{-1}-2n^0=3m^2n-2m^{-2}n^{-1}+1\).

Answer

a) \(2x^3-1-6x^{-3}\) b) \(3m^2n-2m^{-2}n^{-1}+1\)
5246188
Expand, combine like terms, and write the result in descending powers of \(y\). Assume \(y\ne0\). \((4y^{-2}-2y^{-1}+3)(y^2+2y)\)

Hints

- Multiply every term in the first factor by every term in the second. - Use \(y^0=1\). - Combine terms with the same exponent, then order from greatest exponent to least.

Solution

1. Expand: \(4y^0+8y^{-1}-2y-4y^0+3y^2+6y\). 2. The constant terms cancel, and \(-2y+6y=4y\). 3. In descending powers, the result is \(3y^2+4y+8y^{-1}\).

Answer

\(3y^2+4y+8y^{-1}\)
5246198
Simplify. Assume all expressions are defined. a) \((-x^{-4})^{-2}\) b) \(\frac{(-1)^{k+2}}{(-1)^k}\), where \(k\in\mathbb{Z}\) c) \(\left(\frac{2a^2}{3b^{-1}}\right)^{-3}\)

Hints

- Apply an outside exponent to every factor. - Subtract exponents when dividing like bases. - A negative exponent takes the reciprocal.

Solution

1. \((-x^{-4})^{-2}=(-1)^{-2}x^8=x^8\). 2. \(\frac{(-1)^{k+2}}{(-1)^k}=(-1)^2=1\). 3. First, \(\frac{2a^2}{3b^{-1}}=\frac{2a^2b}{3}\). Taking the reciprocal and cubing gives \(\left(\frac{3}{2a^2b}\right)^3=\frac{27}{8a^6b^3}\).

Answer

a) \(x^8\) b) \(1\) c) \(\frac{27}{8a^6b^3}\)
5246208
Simplify using exponent properties. Assume \(a\ne0\), \(x\ne0\), \(y\ne0\), and \(n\in\mathbb{Z}\). a) \(\frac{(-a)^3\cdot a^{-5}}{a^{-2}}\) b) \(\left[\left(-\frac{x}{y}\right)^{-n}\right]^2\) c) \(\frac{5^{2n+1}}{25^n}\)

Hints

- Determine the sign of a negative base with an odd or even exponent. - Multiply exponents for a power of a power. - Rewrite \(25\) using base \(5\).

Solution

1. Since \((-a)^3=-a^3\), the quotient is \(-a^{3-5-(-2)}=-a^0=-1\). 2. The power of a power gives \(\left(-\frac{x}{y}\right)^{-2n}\). Since \(-2n\) is even, this equals \(\left(\frac{x}{y}\right)^{-2n}=\frac{y^{2n}}{x^{2n}}\). 3. Rewrite \(25^n=(5^2)^n=5^{2n}\). Then \(\frac{5^{2n+1}}{5^{2n}}=5\).

Answer

a) \(-1\) b) \(\frac{y^{2n}}{x^{2n}}\) c) \(5\)
5246218
Use exponent properties and the distributive property to simplify without parentheses. Assume \(a\ne0\), \(b\ne0\), and \(x\ne0\). 1) \((b^{-4}-b^{-2}+1)b^3\) 2) \((15x^2+5x^0)x^{-2}\) 3) \((ax^{-2}-bx^{-3})\div x^{-5}\) 4) \((2a^{-1}b^2+4a^2b^{-1})\div(2a^{-2}b^{-2})\)

Hints

- Distribute multiplication or division to every term. - Add exponents when multiplying and subtract them when dividing. - Replace a nonzero base to the zero power with \(1\).

Solution

1. Distribute \(b^3\): \(b^{-1}-b+b^3\). 2. Distribute \(x^{-2}\): \(15x^0+5x^{-2}=15+5x^{-2}\). 3. Divide each term by \(x^{-5}\): \(ax^3-bx^2\). 4. Divide each term by \(2a^{-2}b^{-2}\): \(ab^4+2a^4b\).

Answer

1) \(b^{-1}-b+b^3\) 2) \(15+5x^{-2}\) 3) \(ax^3-bx^2\) 4) \(ab^4+2a^4b\)
5246318
For \(x\ne0\), \(y\ne0\), and \(x+y\ne0\), simplify \(A=\frac{x^{-1}+y^{-1}}{(x+y)^{-1}}\cdot(xy)^{-1}\). Then evaluate the result for \(x=2\) and \(y=3\).

Hints

- Rewrite negative exponents as reciprocals. - Use a common denominator for the sum in the numerator. - Dividing by a fraction means multiplying by its reciprocal.

Solution

1. Rewrite the sum: \(x^{-1}+y^{-1}=\frac{x+y}{xy}\), and \((x+y)^{-1}=\frac{1}{x+y}\). 2. The first quotient is \(\frac{x+y}{xy}\div\frac{1}{x+y}=\frac{(x+y)^2}{xy}\). 3. Multiply by \((xy)^{-1}=\frac{1}{xy}\): \(A=\frac{(x+y)^2}{x^2y^2}\). 4. For \(x=2\) and \(y=3\), \(A=\left(\frac{5}{6}\right)^2=\frac{25}{36}\).

Answer

The simplified expression is \(\frac{(x+y)^2}{x^2y^2}\). For \(x=2\) and \(y=3\), the value is \(\frac{25}{36}\).
5246538
For \(x\ne0\), \(y\ne0\), and \(x\ne\pm y\), show that \(A=\left(\frac{x^{-1}-y^{-1}}{x^{-2}-y^{-2}}\right)^{-1}(x+y)^{-1}\) simplifies to \(\frac{1}{xy}\). Then evaluate it for \(x=2\) and \(y=5\).

Hints

- Factor a difference of squares in the denominator. - An exponent of \(-1\) takes the reciprocal. - Rewrite the sum of reciprocals with denominator \(xy\).

Solution

1. Factor the denominator: \(x^{-2}-y^{-2}=(x^{-1}-y^{-1})(x^{-1}+y^{-1})\). 2. Cancel the common factor to get \(\frac{1}{x^{-1}+y^{-1}}\). Applying the outside exponent \(-1\) gives \(x^{-1}+y^{-1}=\frac{x+y}{xy}\). 3. Multiply by \((x+y)^{-1}\): \(\frac{x+y}{xy}\cdot\frac{1}{x+y}=\frac{1}{xy}\). 4. For \(x=2\) and \(y=5\), the value is \(\frac{1}{10}=0.1\).

Answer

The simplified expression is \(\frac{1}{xy}\). For \(x=2\) and \(y=5\), the value is \(0.1\).
5250598
For positive integer \(n\), \(a\ne0\), and \(a^n\ne b^n\), simplify \(\left(\frac{a^n+b^n}{2a^n}-1\right)^{-3}\). Then evaluate it for \(a=2\), \(b=4\), and \(n=2\).

Hints

- Combine the terms inside parentheses first. - A negative exponent takes the reciprocal before applying the positive exponent. - Simplify symbolically before substituting the numbers.

Solution

1. Combine the terms inside parentheses: \(\frac{a^n+b^n-2a^n}{2a^n}=\frac{b^n-a^n}{2a^n}\). 2. Apply the negative exponent: \(\left(\frac{b^n-a^n}{2a^n}\right)^{-3}=\left(\frac{2a^n}{b^n-a^n}\right)^3\). 3. For \(a=2\), \(b=4\), and \(n=2\), the quantity inside the final parentheses is \(\frac{8}{12}=\frac{2}{3}\). Therefore, the value is \(\left(\frac{2}{3}\right)^3=\frac{8}{27}\).

Answer

The simplified expression is \(\left(\frac{2a^n}{b^n-a^n}\right)^3\). The numerical value is \(\frac{8}{27}\).
5279678
Expand and simplify. Assume \(n\), \(k\), and \(m\) are nonnegative integers. 1) \(4a^n(a^3 - 2a^n)\) 2) \(-3x^k(2x^{k+1} + 4x)\) 3) \(\frac{1}{3}y^m(9y^{2m} - 6y)\)

Hints

- Multiply the outside factor by every term inside the parentheses. - Add exponents when multiplying powers with the same base. - Track the negative sign during distribution.

Solution

1. Distribute and add exponents: \(4a^{n+3} - 8a^{2n}\). 2. Distribute: \(-6x^{k+(k+1)} - 12x^{k+1} = -6x^{2k+1} - 12x^{k+1}\). 3. Distribute: \(3y^{m+2m} - 2y^{m+1} = 3y^{3m} - 2y^{m+1}\).

Answer

1) \(4a^{n+3} - 8a^{2n}\) 2) \(-6x^{2k+1} - 12x^{k+1}\) 3) \(3y^{3m} - 2y^{m+1}\)
5279688
Expand and simplify. Assume \(k\), \(n\), \(m\), and \(p\) are integers and \(x\), \(b\), and \(z\) are nonzero. 1) \(x^{k-1}(x^{k+1} + 5x^2)\) 2) \(6b^{2n}\left(\frac{1}{3}b^{1-n} - 2b^n\right)\) 3) \(-2z^m(3z^{p-m} - z)\)

Hints

- Treat exponent expressions as grouped quantities when adding them. - Simplify the exponent sums after distributing. - Track signs, especially when distributing a negative factor.

Solution

1. Distribute and add exponents: \(x^{(k-1)+(k+1)} + 5x^{(k-1)+2} = x^{2k} + 5x^{k+1}\). 2. Distribute: \(2b^{2n+1-n} - 12b^{2n+n} = 2b^{n+1} - 12b^{3n}\). 3. Distribute: \(-6z^{m+p-m} + 2z^{m+1} = -6z^p + 2z^{m+1}\).

Answer

1) \(x^{2k} + 5x^{k+1}\) 2) \(2b^{n+1} - 12b^{3n}\) 3) \(-6z^p + 2z^{m+1}\)
5122348
Compare the expressions \(x^2\) and \(x^3\). a) Calculate both values when \(x = -3\). b) For any negative value of \(x\), which expression is always greater: \(x^2\) or \(x^3\)? Explain using signs. c) Does your conclusion from part b) hold for every positive value of \(x\)? Test \(x = 0.5\) and \(x = 2\).

Hints

- Every positive number is greater than every negative number. - Test both a positive number between \(0\) and \(1\) and a positive number greater than \(1\). - Consider what happens when a positive value is multiplied by a number between \(0\) and \(1\).

Solution

1. For \(x = -3\), \(x^2 = (-3)^2 = 9\) and \(x^3 = (-3)^3 = -27\). 2. For any negative \(x\), \(x^2\) is positive and \(x^3\) is negative. Therefore, \(x^2 > x^3\). 3. For \(x = 0.5\), \(x^2 = 0.25\) and \(x^3 = 0.125\), so \(x^2 > x^3\). 4. For \(x = 2\), \(x^2 = 4\) and \(x^3 = 8\), so \(x^3 > x^2\). Therefore, the conclusion does not hold for every positive \(x\).

Answer

a) \(x^2 = 9\) and \(x^3 = -27\) b) \(x^2\), because it is positive while \(x^3\) is negative for every negative \(x\) c) No. For \(x = 0.5\), \(0.25 > 0.125\), but for \(x = 2\), \(8 > 4\).
5134108
Let \(T=\frac{4a^n b^{-3}}{2a^2b^m}\), where \(a\ne0\) and \(b\ne0\). Find the integer values of \(n\) and \(m\) that make the simplified expression \(2a^3b^{-5}\). Justify your answer using exponent rules.

Hints

- Simplify the coefficient and each variable base separately. - Use the quotient rule to write an equation for each exponent. - Match the resulting exponents to those in the target expression.

Solution

1. Simplify the numerical coefficient: \(4\div2=2\). 2. For base \(a\), the quotient rule gives \(a^n\div a^2=a^{n-2}\). Set \(n-2=3\), so \(n=5\). 3. For base \(b\), the quotient rule gives \(b^{-3}\div b^m=b^{-3-m}\). Set \(-3-m=-5\), so \(m=2\). 4. With \(n=5\) and \(m=2\), the expression simplifies to \(2a^3b^{-5}\).

Answer

\(n=5\) and \(m=2\)
5134168
Assume \(b\ne0\) and \(x\ne0\). a) Find \(n\) so that \(\frac{b^n b^{-2}}{b^5}=b^3\). b) Decide which expression is equivalent to \(4x^{-2}\). Justify your choice by substituting \(x=2\) into the original expression and all three choices. 1. \(\frac{1}{4x^2}\) 2. \(\frac{4}{x^2}\) 3. \(\frac{1}{16x^2}\)

Hints

- Combine the exponents on the left side of part a). - In part b), the exponent applies only to \(x\), not to the coefficient \(4\). - Compare the numerical values after substituting \(x=2\).

Solution

1. For a), simplify the left side: \(\frac{b^{n-2}}{b^5}=b^{n-7}\). 2. Set exponents equal: \(n-7=3\), so \(n=10\). 3. For b), the original expression at \(x=2\) is \(4\cdot2^{-2}=1\). 4. Choice 1 gives \(\frac{1}{4\cdot2^2}=\frac{1}{16}\). 5. Choice 2 gives \(\frac{4}{2^2}=1\). 6. Choice 3 gives \(\frac{1}{16\cdot2^2}=\frac{1}{64}\). 7. Only choice 2 matches, and in general \(4x^{-2}=\frac{4}{x^2}\).

Answer

a) \(n=10\) b) Choice 2: \(\frac{4}{x^2}\)
5134188
Assume each base is nonzero. Find the integer \(n\) that makes each equation true. a) \(z^n\cdot z^5=z^{-3}\) b) \((a^4)^n=\frac{1}{a^8}\) c) \(\frac{b^n}{b^{-2}}=b^5\) d) \(c^{-3}\cdot c^n=1\)

Hints

- Write an equation involving the exponents. - Rewrite a reciprocal using a negative exponent. - Use exponent \(0\) to represent \(1\).

Solution

1. For a), \(n+5=-3\), so \(n=-8\). 2. For b), \(a^{4n}=a^{-8}\), so \(4n=-8\) and \(n=-2\). 3. For c), \(n-(-2)=5\), so \(n=3\). 4. For d), write \(1=c^0\). Then \(-3+n=0\), so \(n=3\).

Answer

a) \(n=-8\) b) \(n=-2\) c) \(n=3\) d) \(n=3\)
5134258
Find \(z\) so that each equation is true. a) \(5^z\cdot\frac{1}{125}=5^{-1}\) b) \((x^{-2})^z x^5=x^{-1}\) for all \(x>0\) with \(x\ne1\) c) \(\left(\frac{2}{3}\right)^{-2}z=1\)

Hints

- Rewrite numerical fractions as powers with a matching base. - Set the exponents equal when the bases are the same. - Use a reciprocal to solve a product equal to \(1\).

Solution

1. For a), write \(\frac{1}{125}=5^{-3}\). Then \(z-3=-1\), so \(z=2\). 2. For b), \((x^{-2})^z x^5=x^{-2z+5}\). Set \(-2z+5=-1\), so \(z=3\). 3. For c), \(\left(\frac{2}{3}\right)^{-2}=\frac{9}{4}\). Solve \(\frac{9}{4}z=1\) to get \(z=\frac{4}{9}\).

Answer

a) \(z=2\) b) \(z=3\) c) \(z=\frac{4}{9}\)
5134288
Complete each task about powers. a) Order the values from least to greatest: \(2^{-2}\), \((-2)^2\), \(2^0\), \((-2)^{-2}\). b) Find \(x\) so that \(5^x\cdot25=5^{-1}\). c) Evaluate mentally by grouping factors: \(2^9\cdot0.5^9\).

Hints

- Evaluate each power exactly before ordering. - Rewrite \(25\) as a power of \(5\). - Combine bases when the exponents are equal.

Solution

1. The values are \(2^{-2}=\frac{1}{4}\), \((-2)^2=4\), \(2^0=1\), and \((-2)^{-2}=\frac{1}{4}\). Therefore, \(2^{-2}=(-2)^{-2}<2^0<(-2)^2\). 2. For b), write \(25=5^2\). Then \(x+2=-1\), so \(x=-3\). 3. For c), use the common exponent: \(2^9\cdot0.5^9=(2\cdot0.5)^9=1\).

Answer

a) \(2^{-2}=(-2)^{-2}<2^0<(-2)^2\) b) \(x=-3\) c) \(1\)
5134348
Assume all variables are nonzero. Simplify completely. Pay close attention to signs and negative exponents. a) \(\frac{4x^{-2}+2x^{-1}}{2x^{-2}}\) b) \((x^{-2}y^3)^2(x^3y^{-4})\) c) \((-a^2)^{-3}a^7\)

Hints

- Split the fraction in part a) into two fractions. - Apply powers before combining like bases. - An odd exponent preserves the sign of a negative base.

Solution

1. For a), split the fraction: \(\frac{4x^{-2}}{2x^{-2}}+\frac{2x^{-1}}{2x^{-2}}=2+x\). 2. For b), \((x^{-2}y^3)^2(x^3y^{-4})=x^{-4}y^6x^3y^{-4}=x^{-1}y^2=\frac{y^2}{x}\). 3. For c), \((-a^2)^{-3}=-a^{-6}\) because the exponent is odd. Then \(-a^{-6}a^7=-a\).

Answer

a) \(x+2\) b) \(\frac{y^2}{x}\) c) \(-a\)
5135398
Assume \(u\ne0\), \(v\ne0\), and \(x\ne0\). a) Simplify \(\frac{(u^{-1}v^2)^3}{u^{-4}v^5}\). b) Find \(n\) so that \(\frac{x^n}{x^{-3}}=x^2\). c) Explain without calculating why \((-3)^{-2}\) is positive while \(-3^{-2}\) is negative.

Hints

- Apply the exponent to each factor inside the parentheses. - Compare exponents after simplifying part b). - Use the order of operations to determine the base in part c).

Solution

1. For a), the numerator is \(u^{-3}v^6\). Dividing gives \(u^{-3-(-4)}v^{6-5}=uv\). 2. For b), the left side is \(x^{n-(-3)}=x^{n+3}\). Set \(n+3=2\), so \(n=-1\). 3. In \((-3)^{-2}\), the negative sign is part of the base, and the even exponent makes the value positive. In \(-3^{-2}\), exponentiation applies to \(3\) before the leading negative sign is applied.

Answer

a) \(uv\) b) \(n=-1\) c) Parentheses make \(-3\) the base in the first expression; the negative sign is outside the power in the second.
5141558
Find the rational number \(x\) that makes the equation true: \(10^4\cdot10^x=0.01\)

Hints

- Rewrite the decimal as a power of \(10\). - Add exponents when multiplying powers with the same base. - Equal powers with the same base have equal exponents.

Solution

1. Write \(0.01\) as a power of \(10\): \(0.01=10^{-2}\). 2. Combine the powers on the left: \(10^4\cdot10^x=10^{4+x}\). 3. Set the exponents equal: \(4+x=-2\). 4. Solve to get \(x=-6\).

Answer

\(x=-6\)
5141568
Find the rational number \(n\) that makes the equation true: \(2^n\cdot8^{-1}=\frac{1}{32}\)

Hints

- Rewrite \(8\) and \(32\) as powers of \(2\). - Apply the power-of-a-power rule. - Compare the exponents after the bases match.

Solution

1. Write every term as a power of \(2\): \(8^{-1}=(2^3)^{-1}=2^{-3}\) and \(\frac{1}{32}=2^{-5}\). 2. Combine the left side: \(2^n\cdot2^{-3}=2^{n-3}\). 3. Set exponents equal: \(n-3=-5\). 4. Solve to get \(n=-2\).

Answer

\(n=-2\)
5245488
Complete the following tasks about properties of exponents. 1. Find an expression \(T\) such that \(T^3 = -8x^6y^{3n}\). 2. Use algebraic steps to determine whether the equation below is true for all \(a, b \ne 0\) and nonnegative integers \(n\) and \(m\): \(\frac{(a^n b)^m}{a^{nm}} = b^m\) 3. Consider \((-x^2)^k\). For which positive integers \(k\) does \((-x^2)^k = x^{2k}\) hold for all real \(x\)? Briefly justify your answer.

Hints

- For part 1, consider the numerical coefficient and each variable factor separately. - For part 2, apply the power of a product and power of a power properties before canceling common factors. - For part 3, test how the sign changes for a few even and odd values of \(k\).

Solution

1. Find a factor whose cube gives each part of the expression: \((-2)^3 = -8\), \((x^2)^3 = x^6\), and \((y^n)^3 = y^{3n}\). Therefore, \(T = -2x^2y^n\). 2. Simplify the left side: \(\frac{(a^n b)^m}{a^{nm}} = \frac{(a^n)^m b^m}{a^{nm}} = \frac{a^{nm}b^m}{a^{nm}} = b^m\). The equation is true under the stated conditions. 3. \((-x^2)^k = (-1)^k(x^2)^k = (-1)^kx^{2k}\). If \(k\) is even, then \((-1)^k = 1\), so the identity holds for every real \(x\). If \(k\) is odd, it fails for every \(x \ne 0\). Therefore, it holds for all real \(x\) exactly when \(k\) is even.

Answer

1. \(T = -2x^2y^n\) 2. The equation is true because the left side simplifies to \(b^m\). 3. The identity holds for all real \(x\) exactly when \(k\) is even.
5246328
For \(a\ne0\), \(b\ne0\), \(a\ne b\), and \(a\ne-b\), simplify \(B=\frac{(a+b)^{-1}}{a^{-1}+b^{-1}}\div\frac{(a-b)^{-1}}{a^{-1}-b^{-1}}\). Then evaluate the result for \(a=5\) and \(b=3\).

Hints

- Simplify the two large quotients separately. - Watch the sign difference between \(a-b\) and \(b-a\). - Divide fractions by multiplying by the reciprocal.

Solution

1. The first quotient is \(\frac{1}{a+b}\div\frac{a+b}{ab}=\frac{ab}{(a+b)^2}\). 2. The second quotient is \(\frac{1}{a-b}\div\frac{b-a}{ab}=-\frac{ab}{(a-b)^2}\). 3. Divide the two results: \(\frac{ab}{(a+b)^2}\div\left(-\frac{ab}{(a-b)^2}\right)=-\frac{(a-b)^2}{(a+b)^2}\). 4. For \(a=5\) and \(b=3\), the value is \(-\frac{(5-3)^2}{(5+3)^2}=-\frac{1}{16}\).

Answer

The simplified expression is \(-\frac{(a-b)^2}{(a+b)^2}\). For \(a=5\) and \(b=3\), the value is \(-\frac{1}{16}\).
5246548
For positive integer \(n\), nonzero \(a\) and \(b\), and \(a^n\ne b^n\), simplify without negative exponents: \(T=\left(\frac{a^{-n}+b^{-n}}{a^{-n}-b^{-n}}-1\right)^{-1}\). Then evaluate the result for \(a=2\), \(b=6\), and \(n=2\).

Hints

- Combine the fraction and \(1\) using a common denominator. - An outside exponent of \(-1\) takes the reciprocal. - Convert ratios of equal negative powers to positive powers.

Solution

1. Combine the expression inside parentheses: \(\frac{a^{-n}+b^{-n}-(a^{-n}-b^{-n})}{a^{-n}-b^{-n}}=\frac{2b^{-n}}{a^{-n}-b^{-n}}\). 2. Take the reciprocal: \(T=\frac{a^{-n}-b^{-n}}{2b^{-n}}\). 3. Remove negative exponents: \(T=\frac{b^n}{2a^n}-\frac{1}{2}=\frac{b^n-a^n}{2a^n}\). 4. For \(a=2\), \(b=6\), and \(n=2\), \(T=\frac{36-4}{8}=4\).

Answer

The simplified expression is \(\frac{b^n-a^n}{2a^n}\). The numerical value is \(4\).

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