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Polynomial arithmetic

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5227719
Combine like terms. 1) \(12a-7a+3a\) 2) \(-5x^2+9x^2-6x^2\) 3) \(4.5y-1.2y-2.1y\)

Hints

- Each expression contains like terms. - Combine the numerical coefficients. - Keep track of each coefficient’s sign.

Solution

1. \(12-7+3=8\), so the result is \(8a\). 2. \(-5+9-6=-2\), so the result is \(-2x^2\). 3. \(4.5-1.2-2.1=1.2\), so the result is \(1.2y\).

Answer

1) \(8a\) 2) \(-2x^2\) 3) \(1.2y\)
5229479
Combine like terms. 1) \(12x^2-(-8x^2)\) 2) \(-15y^3-(-10y^3)\) 3) \(7a^4-(+11a^4)\) 4) \(-b^2-(-b^2)\)

Hints

- Subtracting a negative term changes to addition. - Combine the signed coefficients. - Opposite terms cancel.

Solution

1. \(12x^2-(-8x^2)=12x^2+8x^2=20x^2\). 2. \(-15y^3-(-10y^3)=-15y^3+10y^3=-5y^3\). 3. \(7a^4-(+11a^4)=7a^4-11a^4=-4a^4\). 4. \(-b^2-(-b^2)=-b^2+b^2=0\).

Answer

1) \(20x^2\) 2) \(-5y^3\) 3) \(-4a^4\) 4) \(0\)
5154799
Combine like terms. \(2.4x^2y-\frac{3}{5}xy^2+0.6x^2y+\frac{1}{10}xy^2\)

Hints

- Compare both the variables and their exponents when identifying like terms. - Rewrite the fractional coefficients with a common denominator. - Combine each group of like terms separately.

Solution

1. The \(x^2y\)-terms and \(xy^2\)-terms are not like terms, so combine them separately. 2. Combine the \(x^2y\)-terms: \(2.4x^2y+0.6x^2y=3x^2y\). 3. Combine the \(xy^2\)-terms: \(-\frac{3}{5}+\frac{1}{10}=-\frac{6}{10}+\frac{1}{10}=-\frac{5}{10}=-0.5\). 4. The simplified expression is \(3x^2y-0.5xy^2\).

Answer

\(3x^2y-0.5xy^2\)
5227559
Combine like terms. \(0.7x^2-5x+1.3x^2+2x-11\)

Hints

- Like terms have the same variables raised to the same powers. - Combine the coefficients while keeping their signs. - The constant term remains separate.

Solution

1. Combine the \(x^2\)-terms: \(0.7x^2+1.3x^2=2x^2\). 2. Combine the \(x\)-terms: \(-5x+2x=-3x\). 3. Keep the constant term \(-11\). The simplified polynomial is \(2x^2-3x-11\).

Answer

\(2x^2-3x-11\)
5227659
Combine like terms. a) \(4.2z^5-6z^5+1\frac{4}{5}z^5\) b) \(2\frac{3}{4}x^2-1.5x^2-3x^2\)

Hints

- Each part contains like terms with the same variable and exponent. - Convert mixed numbers to decimals or improper fractions. - A term disappears when its coefficient is zero.

Solution

1. For part a, convert \(1\frac{4}{5}\) to \(1.8\). Then \(4.2-6+1.8=0\), so the expression equals \(0\). 2. For part b, convert \(2\frac{3}{4}\) to \(2.75\). Then \(2.75-1.5-3=-1.75\), so the result is \(-1.75x^2\).

Answer

a) \(0\) b) \(-1.75x^2\), or \(-1\frac{3}{4}x^2\)
5227669
Combine like terms. a) \(\frac{7}{12}a^3-\frac{1}{4}a^3-\frac{2}{3}a^3\) b) \(-\frac{1}{2}b^4+\frac{5}{8}b^4-\frac{3}{4}b^4\)

Hints

- Use a common denominator to combine fractional coefficients. - Keep track of every negative sign. - Simplify the final coefficient when possible.

Solution

1. For part a, use denominator \(12\): \(\frac{7}{12}-\frac{3}{12}-\frac{8}{12}=-\frac{4}{12}=-\frac{1}{3}\). The result is \(-\frac{1}{3}a^3\). 2. For part b, use denominator \(8\): \(-\frac{4}{8}+\frac{5}{8}-\frac{6}{8}=-\frac{5}{8}\). The result is \(-\frac{5}{8}b^4\).

Answer

a) \(-\frac{1}{3}a^3\) b) \(-\frac{5}{8}b^4\)
5227679
Combine like terms. 1) \(4.2x^2-5.8x^2+0.6x^2\) 2) \(-0.75ab^2+1.5ab^2-0.25ab^2\) 3) \(12y^5-15y^5-3y^5+7y^5\) 4) \(0.15z^3-0.4z^3+0.25z^3\)

Hints

- Each group consists of like terms. - Combine only the coefficients. - Remember that coefficients of \(1\), \(-1\), and \(0\) have special written forms.

Solution

1. \(4.2-5.8+0.6=-1\), so the result is \(-x^2\). 2. \(-0.75+1.5-0.25=0.5\), so the result is \(0.5ab^2\). 3. \(12-15-3+7=1\), so the result is \(y^5\). 4. \(0.15-0.4+0.25=0\), so the result is \(0\).

Answer

1) \(-x^2\) 2) \(0.5ab^2\) 3) \(y^5\) 4) \(0\)
5227729
Combine like terms. 1) \(10m-3n-4m+7n\) 2) \(2x^2+5x-7x^2-x\) 3) \(12ab-5ba+4a\) 4) \(\frac{3}{8}z+\frac{1}{4}-\frac{1}{8}z+\frac{3}{4}\)

Hints

- Like terms must have identical variable parts and exponents. - Use the commutative property to recognize that \(ab=ba\). - Combine constant terms separately.

Solution

1. Combine the \(m\)-terms and \(n\)-terms: \(10m-4m=6m\) and \(-3n+7n=4n\). The result is \(6m+4n\). 2. Combine terms with matching powers: \(2x^2-7x^2=-5x^2\) and \(5x-x=4x\). The result is \(-5x^2+4x\). 3. Since \(ba=ab\), \(12ab-5ba=7ab\). The term \(4a\) is not like an \(ab\)-term, so the result is \(7ab+4a\). 4. Combine the \(z\)-terms and constants: \(\frac{3}{8}z-\frac{1}{8}z=\frac{1}{4}z\) and \(\frac{1}{4}+\frac{3}{4}=1\). The result is \(\frac{1}{4}z+1\).

Answer

1) \(6m+4n\) 2) \(-5x^2+4x\) 3) \(7ab+4a\) 4) \(\frac{1}{4}z+1\)
5227739
Combine like terms. 1) \(18x^2+7x-5x^2-7x\) 2) \(-4a-9-3a+2\) 3) \(5y^3-2y+4y-3y^3\) 4) \(-2m^2-n+5m^2-4n\)

Hints

- Group terms with the same variable parts and exponents. - Keep each term’s sign with its coefficient. - Terms with different powers cannot be combined.

Solution

1. \(18x^2-5x^2=13x^2\), and \(7x-7x=0\). The result is \(13x^2\). 2. \(-4a-3a=-7a\), and \(-9+2=-7\). The result is \(-7a-7\). 3. \(5y^3-3y^3=2y^3\), and \(-2y+4y=2y\). The result is \(2y^3+2y\). 4. \(-2m^2+5m^2=3m^2\), and \(-n-4n=-5n\). The result is \(3m^2-5n\).

Answer

1) \(13x^2\) 2) \(-7a-7\) 3) \(2y^3+2y\) 4) \(3m^2-5n\)
5227749
Combine like terms. 1) \(3.5z^2-1.2z+1.5z^2-0.8z\) 2) \(\frac{2}{5}b-\frac{1}{2}c+\frac{3}{5}b-\frac{3}{2}c\) 3) \(9pq-4p+2qp-p\) 4) \(x^4-3x^2+2x^4+3x^2\)

Hints

- Combine coefficients only when the variable parts match exactly. - Use the commutative property to compare \(pq\) and \(qp\). - Terms can cancel when their coefficients are opposites.

Solution

1. Combine by power: \(3.5z^2+1.5z^2=5z^2\) and \(-1.2z-0.8z=-2z\). The result is \(5z^2-2z\). 2. \(\frac{2}{5}b+\frac{3}{5}b=b\), and \(-\frac{1}{2}c-\frac{3}{2}c=-2c\). The result is \(b-2c\). 3. Since \(qp=pq\), \(9pq+2qp=11pq\), and \(-4p-p=-5p\). The result is \(11pq-5p\). 4. \(x^4+2x^4=3x^4\), and the \(x^2\)-terms cancel. The result is \(3x^4\).

Answer

1) \(5z^2-2z\) 2) \(b-2c\) 3) \(11pq-5p\) 4) \(3x^4\)
5227779
Combine like terms. 1) \(9a-4b+3a-7b+a\) 2) \(1.2x^2-0.5x+0.8x^2+1.5x-x^2\) 3) \(\frac{3}{8}u^2v-\frac{1}{2}uv^2+\frac{5}{8}u^2v+\frac{3}{4}uv^2\)

Hints

- Like terms have exactly the same variables and exponents. - A variable term with no visible coefficient has coefficient \(1\). - Combine each group of coefficients separately.

Solution

1. Combine the \(a\)-terms and \(b\)-terms: \(9a+3a+a=13a\) and \(-4b-7b=-11b\). The result is \(13a-11b\). 2. Combine by power: \(1.2x^2+0.8x^2-x^2=x^2\), and \(-0.5x+1.5x=x\). The result is \(x^2+x\). 3. Combine each variable part separately: \(\frac{3}{8}u^2v+\frac{5}{8}u^2v=u^2v\), and \(-\frac{1}{2}uv^2+\frac{3}{4}uv^2=\frac{1}{4}uv^2\). The result is \(u^2v+\frac{1}{4}uv^2\).

Answer

1) \(13a-11b\) 2) \(x^2+x\) 3) \(u^2v+\frac{1}{4}uv^2\)
5227789
Combine like terms. 1) \(17x^2y-8xy+3x^2y-2xy+xy\) 2) \(2.5a^3b-1.4ab^3+0.5a^3b+1.4ab^3-3a^3b\) 3) \(\frac{2}{3}z^2-\frac{1}{4}z+\frac{1}{3}z^2-\frac{3}{4}z+5\)

Hints

- Compare the complete variable parts, including exponents. - A group of like terms cancels when its coefficients add to zero. - Keep constant terms separate.

Solution

1. Combine the \(x^2y\)-terms and \(xy\)-terms: \(17+3=20\) and \(-8-2+1=-9\). The result is \(20x^2y-9xy\). 2. The \(a^3b\)-coefficients add to \(2.5+0.5-3=0\), and the \(ab^3\)-coefficients add to \(-1.4+1.4=0\). The expression simplifies to \(0\). 3. The \(z^2\)-coefficients add to \(\frac{2}{3}+\frac{1}{3}=1\), and the \(z\)-coefficients add to \(-\frac{1}{4}-\frac{3}{4}=-1\). The result is \(z^2-z+5\).

Answer

1) \(20x^2y-9xy\) 2) \(0\) 3) \(z^2-z+5\)
5227879
Combine like terms. \(\frac{1}{3}x^2y-\frac{5}{2}xy^2+\frac{5}{6}x^2y-\frac{1}{4}xy^2-\frac{1}{6}x^2y\)

Hints

- Group terms with identical variables and exponents. - Use a common denominator for fractional coefficients. - Keep each coefficient’s sign.

Solution

1. Group the \(x^2y\)-terms and \(xy^2\)-terms separately. 2. For \(x^2y\), \(\frac{1}{3}+\frac{5}{6}-\frac{1}{6}=\frac{2}{6}+\frac{5}{6}-\frac{1}{6}=1\). 3. For \(xy^2\), \(-\frac{5}{2}-\frac{1}{4}=-\frac{10}{4}-\frac{1}{4}=-\frac{11}{4}\). 4. The simplified expression is \(x^2y-\frac{11}{4}xy^2\).

Answer

\(x^2y-\frac{11}{4}xy^2\)
5228089
Combine like terms. \(2.4a^2-1.5ab+0.6a^2+3ab-a^2\)

Hints

- \(a^2\) and \(ab\) are different variable parts. - The coefficient of \(-a^2\) is \(-1\). - Combine each group of coefficients separately.

Solution

1. Combine the \(a^2\)-terms: \(2.4+0.6-1=2\). 2. Combine the \(ab\)-terms: \(-1.5+3=1.5\). 3. The simplified expression is \(2a^2+1.5ab\).

Answer

\(2a^2+1.5ab\)
5228099
Combine like terms. 1) \(14z^3+(-8z^3)-6z^3\) 2) \(-4.2xy-(+1.5xy)+0.7xy\) 3) \(\frac{3}{4}b^2-\frac{1}{2}b^2+\frac{1}{4}b^2\)

Hints

- Combine the signed coefficients of the like terms. - Rewrite fractions with a common denominator. - A term with coefficient zero disappears.

Solution

1. \(14-8-6=0\), so the expression equals \(0\). 2. \(-4.2-1.5+0.7=-5\), so the result is \(-5xy\). 3. \(\frac{3}{4}-\frac{1}{2}+\frac{1}{4}=\frac{3}{4}-\frac{2}{4}+\frac{1}{4}=\frac{1}{2}\), so the result is \(\frac{1}{2}b^2\).

Answer

1) \(0\) 2) \(-5xy\) 3) \(\frac{1}{2}b^2\)
5228139
Check each calculation. Identify the correct results and correct the incorrect ones. 1) \(5a-8a=-3a\) 2) \(\frac{1}{2}x+\frac{1}{4}x=\frac{2}{6}x\) 3) \(-0.3y+y=0.7y\) 4) \(b^2+b^2=2b^4\) 5) \(4mn-mn=3mn\)

Hints

- Add fractions by using a common denominator. - A variable term with no visible coefficient has coefficient \(1\). - Adding like terms does not change their exponents.

Solution

1. Statement 1 is correct because \(5-8=-3\). 2. Statement 2 is incorrect. Use a common denominator: \(\frac{1}{2}x+\frac{1}{4}x=\frac{2}{4}x+\frac{1}{4}x=\frac{3}{4}x\). The original work incorrectly added the denominators. 3. Statement 3 is correct because \(-0.3+1=0.7\). 4. Statement 4 is incorrect. Adding like terms changes the coefficient, not the exponent: \(b^2+b^2=2b^2\). 5. Statement 5 is correct because \(4-1=3\).

Answer

1) Correct. 2) Incorrect; \(\frac{3}{4}x\). 3) Correct. 4) Incorrect; \(2b^2\). 5) Correct.
5228149
Combine like terms. a) \(-1.2k+2.5k-0.8k\) b) \(\frac{2}{3}z-\frac{1}{6}z-z\) c) \(1.5x^2-2x^2+0.5x^2\) d) \(\frac{3}{4}ab+\frac{1}{8}ab-ab\)

Hints

- Combine the coefficients separately from the variable parts. - An unwritten coefficient is \(1\). - Use a common denominator for fractional coefficients.

Solution

1. For part a, \(-1.2+2.5-0.8=0.5\), so the result is \(0.5k\). 2. For part b, \(\frac{2}{3}-\frac{1}{6}-1=\frac{4}{6}-\frac{1}{6}-\frac{6}{6}=-\frac{1}{2}\), so the result is \(-\frac{1}{2}z\). 3. For part c, \(1.5-2+0.5=0\), so the expression equals \(0\). 4. For part d, \(\frac{3}{4}+\frac{1}{8}-1=\frac{6}{8}+\frac{1}{8}-\frac{8}{8}=-\frac{1}{8}\), so the result is \(-\frac{1}{8}ab\).

Answer

a) \(0.5k\) b) \(-\frac{1}{2}z\) c) \(0\) d) \(-\frac{1}{8}ab\)
5228179
Combine like terms. \(12ab^2+(-5ab^2)-8ab^2+(-2ab^2)\)

Hints

- Confirm that every term has the same variables and exponents. - Rewrite additions of negative terms as subtraction. - Combine the signed coefficients.

Solution

1. All terms have the same variable part \(ab^2\). 2. Combine the coefficients: \(12-5-8-2=-3\). 3. The simplified expression is \(-3ab^2\).

Answer

\(-3ab^2\)
5228189
Combine like terms. \(0.7x^3-1.2x+(-0.5x^3)+2.5x-0.4x^3\)

Hints

- Group terms with identical powers of \(x\). - Keep each coefficient’s sign. - Combine the cubic and linear terms separately.

Solution

1. Combine the \(x^3\)-terms: \(0.7-0.5-0.4=-0.2\). 2. Combine the \(x\)-terms: \(-1.2+2.5=1.3\). 3. The simplified expression is \(-0.2x^3+1.3x\).

Answer

\(-0.2x^3+1.3x\)
5228239
Combine like terms. \((+4.8x^2)+(-2.5x)+(-1.3x^2)+(+3.7)+(-0.5x)+(-1.2)\)

Hints

- Group terms with matching variables and exponents. - Combine constants separately. - Keep the signs attached to their terms.

Solution

1. Combine the \(x^2\)-terms: \(4.8x^2-1.3x^2=3.5x^2\). 2. Combine the \(x\)-terms: \(-2.5x-0.5x=-3x\). 3. Combine the constants: \(3.7-1.2=2.5\). 4. The simplified expression is \(3.5x^2-3x+2.5\).

Answer

\(3.5x^2-3x+2.5\)
5228549
Combine like terms. \(-\frac{4}{9}u^2v+\frac{1}{2}uv^2-\frac{1}{3}u^2v-\frac{3}{10}uv^2+\frac{1}{5}uv^2\)

Hints

- \(u^2v\) and \(uv^2\) are not like terms. - Use common denominators for the fractional coefficients. - Keep each negative sign with its coefficient.

Solution

1. Combine the \(u^2v\)-terms: \(-\frac{4}{9}-\frac{1}{3}=-\frac{4}{9}-\frac{3}{9}=-\frac{7}{9}\). 2. Combine the \(uv^2\)-terms: \(\frac{1}{2}-\frac{3}{10}+\frac{1}{5}=\frac{5}{10}-\frac{3}{10}+\frac{2}{10}=\frac{2}{5}\). 3. The simplified expression is \(-\frac{7}{9}u^2v+\frac{2}{5}uv^2\).

Answer

\(-\frac{7}{9}u^2v+\frac{2}{5}uv^2\)
5228599
Combine like terms. \(7.5m^2-4.2mn+1.6n^2-5.8m^2+2.3mn-3.1n^2\)

Hints

- Group terms with identical variable parts. - Combine the signed decimal coefficients. - Keep the three variable parts separate.

Solution

1. Combine the \(m^2\)-terms: \(7.5-5.8=1.7\). 2. Combine the \(mn\)-terms: \(-4.2+2.3=-1.9\). 3. Combine the \(n^2\)-terms: \(1.6-3.1=-1.5\). 4. The simplified expression is \(1.7m^2-1.9mn-1.5n^2\).

Answer

\(1.7m^2-1.9mn-1.5n^2\)
5228919
Remove the parentheses and combine like terms. 1) \((12a+7b)+(5a-9b)\) 2) \((4x^2-3x+2)+(2x^2+5x-6)\) 3) \((2.4y-1.5)+(0.6y+3.8)\)

Hints

- A plus sign before parentheses leaves the signs inside unchanged. - Combine only terms with matching variables and exponents. - Combine constants separately.

Solution

1. Combine matching variable terms: \(12a+5a=17a\) and \(7b-9b=-2b\). The result is \(17a-2b\). 2. Combine by degree: \(4x^2+2x^2=6x^2\), \(-3x+5x=2x\), and \(2-6=-4\). The result is \(6x^2+2x-4\). 3. Combine the \(y\)-terms and constants: \(2.4y+0.6y=3y\) and \(-1.5+3.8=2.3\). The result is \(3y+2.3\).

Answer

1) \(17a-2b\) 2) \(6x^2+2x-4\) 3) \(3y+2.3\)
5228929
Add and combine like terms. 1) \((5r^2s-2rs^2)+(3rs^2-4r^2s)\) 2) \((a^3+4a^2-7)+(2a^2-a^3+7)\) 3) \((2x+3y-4z)+(x-5y+2z)+(2y+2z)\)

Hints

- Combine only terms with identical variables and exponents. - Opposite terms cancel. - Group each variable part before adding coefficients.

Solution

1. Combine matching variable parts: \(5r^2s-4r^2s=r^2s\) and \(-2rs^2+3rs^2=rs^2\). The result is \(r^2s+rs^2\). 2. The \(a^3\)-terms cancel, \(4a^2+2a^2=6a^2\), and the constants cancel. The result is \(6a^2\). 3. \(2x+x=3x\), \(3y-5y+2y=0\), and \(-4z+2z+2z=0\). The result is \(3x\).

Answer

1) \(r^2s+rs^2\) 2) \(6a^2\) 3) \(3x\)
5228999
Add each pair of expressions and simplify. 1) \(9y-12\) and \(4y+15\) 2) \(-3a+8b\) and \(3a-10b\) 3) \(2.5x^2-4x\) and \(-1.5x^2+4x-7\) 4) \(\frac{1}{2}k+\frac{2}{3}\) and \(\frac{1}{4}k-\frac{1}{6}\)

Hints

- Group terms with matching variable parts. - Use common denominators for fractional coefficients and constants. - Opposite terms cancel.

Solution

1. \((9y-12)+(4y+15)=13y+3\). 2. \((-3a+8b)+(3a-10b)=-2b\). 3. \((2.5x^2-4x)+(-1.5x^2+4x-7)=x^2-7\). 4. \(\left(\frac{1}{2}k+\frac{2}{3}\right)+\left(\frac{1}{4}k-\frac{1}{6}\right)=\frac{3}{4}k+\frac{1}{2}\).

Answer

1) \(13y+3\) 2) \(-2b\) 3) \(x^2-7\) 4) \(\frac{3}{4}k+\frac{1}{2}\)
5229019
Add the three expressions and combine like terms. \(T_1=7.2a^2-3.5ab+1.4b^2\) \(T_2=-2.8a^2+4.2ab-0.9b^2\) \(T_3=0.6a^2-1.1ab-1.2b^2\)

Hints

- Group terms with identical variable parts. - Add the signed decimal coefficients. - Keep \(a^2\), \(ab\), and \(b^2\) separate.

Solution

1. Combine the \(a^2\)-coefficients: \(7.2-2.8+0.6=5\). 2. Combine the \(ab\)-coefficients: \(-3.5+4.2-1.1=-0.4\). 3. Combine the \(b^2\)-coefficients: \(1.4-0.9-1.2=-0.7\). 4. The sum is \(5a^2-0.4ab-0.7b^2\).

Answer

\(5a^2-0.4ab-0.7b^2\)
5229489
Find the expression that belongs in each blank. 1) \(4.5z^2-\underline{\hspace{1cm}}=7z^2\) 2) \(\underline{\hspace{1cm}}-(-3x^3)=-x^3\) 3) \(-1.2a-0.8a=\underline{\hspace{1cm}}\)

Hints

- Treat each blank as an unknown expression. - Pay attention to subtraction of negative terms. - Substitute each result to verify it.

Solution

1. Let the missing expression be \(M\). Then \(M=4.5z^2-7z^2=-2.5z^2\). Check: \(4.5z^2-(-2.5z^2)=7z^2\). 2. Let the missing expression be \(N\). Then \(N+3x^3=-x^3\), so \(N=-4x^3\). 3. Combine like terms: \(-1.2a-0.8a=-2a\).

Answer

1) \(-2.5z^2\) 2) \(-4x^3\) 3) \(-2a\)
5229519
Combine like terms. 1) \(5.4k^2-(+2.1k^2)\) 2) \(-3.8x^4-(-5.2x^4)\) 3) \(0.25m^2n-0.75m^2n\)

Hints

- Combine the numerical coefficients. - Subtracting a negative coefficient changes to addition. - Keep the variable part unchanged.

Solution

1. \(5.4-2.1=3.3\), so the result is \(3.3k^2\). 2. \(-3.8-(-5.2)=-3.8+5.2=1.4\), so the result is \(1.4x^4\). 3. \(0.25-0.75=-0.5\), so the result is \(-0.5m^2n\).

Answer

1) \(3.3k^2\) 2) \(1.4x^4\) 3) \(-0.5m^2n\)
5229529
Combine like terms. 1) \(\frac{3}{4}y^3-0.5y^3+(-1.25y^3)\) 2) \(6.7a^2b-2.3ab^2-4.7a^2b+0.3ab^2\)

Hints

- Convert fractional and decimal coefficients to a common form. - \(a^2b\) and \(ab^2\) are different variable parts. - A coefficient of \(-1\) is written as a minus sign.

Solution

1. Convert \(\frac{3}{4}\) to \(0.75\): \(0.75-0.5-1.25=-1\). The result is \(-y^3\). 2. Combine the \(a^2b\)-terms: \(6.7-4.7=2\). Combine the \(ab^2\)-terms: \(-2.3+0.3=-2\). The result is \(2a^2b-2ab^2\).

Answer

1) \(-y^3\) 2) \(2a^2b-2ab^2\)
5229549
Combine like terms. 1) \(12xy-15xy+4xy\) 2) \(-5a^2b-(-8a^2b)-3a^2b\) 3) \(4.5z-(-1.5z)-7z\) 4) \(\frac{1}{2}x-\left(-\frac{3}{2}x\right)\)

Hints

- Combine only terms with identical variable parts. - Subtracting a negative term changes to addition. - Use common denominators for fractional coefficients.

Solution

1. \(12-15+4=1\), so the result is \(xy\). 2. \(-5-(-8)-3=-5+8-3=0\), so the expression equals \(0\). 3. \(4.5+1.5-7=-1\), so the result is \(-z\). 4. \(\frac{1}{2}+\frac{3}{2}=2\), so the result is \(2x\).

Answer

1) \(xy\) 2) \(0\) 3) \(-z\) 4) \(2x\)
5229559
Remove the parentheses and combine like terms. a) \(9k-(4k+3m)\) b) \((2x-8y)-(5x-3y)\) c) \(15u^2-(7u^2-10u)-4u\)

Hints

- A negative sign before parentheses reverses every sign inside. - Combine only matching variable parts. - Keep \(u^2\)-terms separate from \(u\)-terms.

Solution

1. For part a, distribute the negative sign: \(9k-4k-3m=5k-3m\). 2. For part b, distribute the negative sign and combine like terms: \(2x-8y-5x+3y=-3x-5y\). 3. For part c, \(15u^2-7u^2+10u-4u=8u^2+6u\).

Answer

a) \(5k-3m\) b) \(-3x-5y\) c) \(8u^2+6u\)
5229619
Subtract the expressions and combine like terms. a) \((6x-9y+4z)-(15x+3y-8z)\) b) \((4a^2-ab+2b^2)-(4a^2+5ab-3b^2)\)

Hints

- Reverse every sign in the expression being subtracted. - Group terms with identical variable parts. - Check whether any terms cancel.

Solution

1. For part a, distribute the negative sign: \(6x-9y+4z-15x-3y+8z\). 2. Combine like terms: \((6-15)x+(-9-3)y+(4+8)z=-9x-12y+12z\). 3. For part b, distribute the negative sign: \(4a^2-ab+2b^2-4a^2-5ab+3b^2\). 4. Combine like terms: the \(a^2\)-terms cancel, \(-ab-5ab=-6ab\), and \(2b^2+3b^2=5b^2\).

Answer

a) \(-9x-12y+12z\) b) \(-6ab+5b^2\)
5229639
Subtract the polynomials and combine like terms. \(\left(\frac{3}{10}x^2-\frac{2}{3}xy+\frac{5}{6}y^2\right)-\left(\frac{1}{5}x^2+\frac{1}{4}xy-\frac{1}{2}y^2\right)\)

Hints

- Reverse every sign in the second polynomial. - Combine terms with identical variable parts. - Use common denominators for fractional coefficients.

Solution

1. Distribute the negative sign: \(\frac{3}{10}x^2-\frac{2}{3}xy+\frac{5}{6}y^2-\frac{1}{5}x^2-\frac{1}{4}xy+\frac{1}{2}y^2\). 2. Combine the \(x^2\)-terms: \(\frac{3}{10}-\frac{1}{5}=\frac{1}{10}\). 3. Combine the \(xy\)-terms: \(-\frac{2}{3}-\frac{1}{4}=-\frac{8}{12}-\frac{3}{12}=-\frac{11}{12}\). 4. Combine the \(y^2\)-terms: \(\frac{5}{6}+\frac{1}{2}=\frac{4}{3}\). 5. The result is \(\frac{1}{10}x^2-\frac{11}{12}xy+\frac{4}{3}y^2\).

Answer

\(\frac{1}{10}x^2-\frac{11}{12}xy+\frac{4}{3}y^2\)
5229659
Subtract the expressions and combine like terms. \((4.7xy-2.3yz+5xz)-(1.2xy+3.7yz-2xz)\)

Hints

- Reverse every sign in the second expression. - Group terms with matching variable products. - Combine the signed decimal coefficients.

Solution

1. Distribute the negative sign: \(4.7xy-2.3yz+5xz-1.2xy-3.7yz+2xz\). 2. Combine the \(xy\)-terms: \(4.7xy-1.2xy=3.5xy\). 3. Combine the \(yz\)-terms: \(-2.3yz-3.7yz=-6yz\). 4. Combine the \(xz\)-terms: \(5xz+2xz=7xz\). 5. The result is \(3.5xy-6yz+7xz\).

Answer

\(3.5xy-6yz+7xz\)
5229679
Subtract the polynomials and simplify. \(\left(4\frac{1}{2}x^2-0.3xy+2y^2\right)-\left(1.75x^2+\frac{4}{5}xy-3\frac{1}{2}y^2\right)\)

Hints

- Convert all coefficients to decimals first. - Reverse every sign in the second polynomial. - Combine the \(x^2\), \(xy\), and \(y^2\) terms separately.

Solution

1. Convert the fractional coefficients: \(4\frac{1}{2}=4.5\), \(\frac{4}{5}=0.8\), and \(3\frac{1}{2}=3.5\). 2. Distribute the negative sign: \(4.5x^2-0.3xy+2y^2-1.75x^2-0.8xy+3.5y^2\). 3. Combine like terms: \((4.5-1.75)x^2+(-0.3-0.8)xy+(2+3.5)y^2\). 4. The result is \(2.75x^2-1.1xy+5.5y^2\).

Answer

\(2.75x^2-1.1xy+5.5y^2\)
5229709
Subtract the polynomials and simplify. \(\left(0.6z^2-\frac{3}{8}z+1\frac{1}{5}\right)-\left(-1.4z^2+0.125z+1.2\right)\)

Hints

- Convert the fraction and mixed number to decimals. - Reverse every sign in the second polynomial. - Check whether the constant terms cancel.

Solution

1. Convert the fractional values: \(\frac{3}{8}=0.375\) and \(1\frac{1}{5}=1.2\). 2. Distribute the negative sign: \(0.6z^2-0.375z+1.2+1.4z^2-0.125z-1.2\). 3. Combine like terms: \((0.6+1.4)z^2+(-0.375-0.125)z+(1.2-1.2)\). 4. The result is \(2z^2-0.5z\).

Answer

\(2z^2-0.5z\)
5229719
Subtract and combine like terms. 1) \(\left(1\frac{3}{4}x-\frac{2}{5}y\right)-\left(\frac{1}{2}x+\frac{1}{10}y\right)\) 2) \(\left(\frac{2}{3}a^2-\frac{1}{4}ab+\frac{1}{2}b^2\right)-\left(\frac{1}{6}a^2+\frac{3}{4}ab-b^2\right)\)

Hints

- Convert mixed numbers to improper fractions. - Reverse every sign in the expression being subtracted. - Use common denominators before combining coefficients.

Solution

1. Convert \(1\frac{3}{4}\) to \(\frac{7}{4}\), distribute the negative sign, and combine like terms: \(\left(\frac{7}{4}-\frac{1}{2}\right)x+\left(-\frac{2}{5}-\frac{1}{10}\right)y=\frac{5}{4}x-\frac{1}{2}y\). 2. Distribute the negative sign and combine like terms: \(\left(\frac{2}{3}-\frac{1}{6}\right)a^2+\left(-\frac{1}{4}-\frac{3}{4}\right)ab+\left(\frac{1}{2}+1\right)b^2\). 3. The second result is \(\frac{1}{2}a^2-ab+\frac{3}{2}b^2\).

Answer

1) \(\frac{5}{4}x-\frac{1}{2}y\) 2) \(\frac{1}{2}a^2-ab+\frac{3}{2}b^2\)
5229749
Simplify the expression. \(10a^2-[4a^2+6a-(a^2-2a)]\)

Hints

- Begin with the innermost parentheses. - Combine like terms inside the brackets before removing them. - Reverse every sign when subtracting the bracketed expression.

Solution

1. Remove the inner parentheses: \(10a^2-[4a^2+6a-a^2+2a]\). 2. Combine like terms inside the brackets: \(10a^2-[3a^2+8a]\). 3. Distribute the negative sign outside the brackets: \(10a^2-3a^2-8a\). 4. Combine the quadratic terms to obtain \(7a^2-8a\).

Answer

\(7a^2-8a\)
5229759
Remove the parentheses and combine like terms. \((4x^2-3x+5)-(2x^2+5x-7)+(x^2-4x-1)\)

Hints

- Reverse every sign in the polynomial being subtracted. - A plus sign before parentheses leaves the signs unchanged. - Group terms by degree.

Solution

1. Remove the parentheses: \(4x^2-3x+5-2x^2-5x+7+x^2-4x-1\). 2. Combine the quadratic terms: \((4-2+1)x^2=3x^2\). 3. Combine the linear terms: \((-3-5-4)x=-12x\). 4. Combine the constants: \(5+7-1=11\). 5. The result is \(3x^2-12x+11\).

Answer

\(3x^2-12x+11\)
5229799
Simplify the expression. \(4x^2-[3y^2-(2x^2+5xy-y^2)+(x^2-5xy)]\)

Hints

- Work from the inner parentheses outward. - Simplify the entire bracketed expression before subtracting it. - Reverse every sign when removing the outer brackets.

Solution

1. Simplify inside the brackets: \(3y^2-2x^2-5xy+y^2+x^2-5xy\). 2. Combine like terms inside the brackets: \(-x^2-10xy+4y^2\). 3. Subtract the bracketed expression: \(4x^2-[-x^2-10xy+4y^2]=4x^2+x^2+10xy-4y^2\). 4. The result is \(5x^2+10xy-4y^2\).

Answer

\(5x^2+10xy-4y^2\)
5229839
Remove the parentheses and combine like terms. \((4.5x^2y-2.3xy^2+1.2x^2y^2)-(1.8x^2y+3.7xy^2-0.5x^2y^2)\)

Hints

- Reverse every sign in the polynomial being subtracted. - Group terms whose variable parts, including exponents, are identical. - Combine only the coefficients of like terms.

Solution

1. Distribute the negative sign before the second polynomial: \(4.5x^2y-2.3xy^2+1.2x^2y^2-1.8x^2y-3.7xy^2+0.5x^2y^2\). 2. Combine the \(x^2y\) terms: \((4.5-1.8)x^2y=2.7x^2y\). 3. Combine the \(xy^2\) terms: \((-2.3-3.7)xy^2=-6xy^2\). 4. Combine the \(x^2y^2\) terms: \((1.2+0.5)x^2y^2=1.7x^2y^2\). 5. The result is \(2.7x^2y-6xy^2+1.7x^2y^2\).

Answer

\(2.7x^2y-6xy^2+1.7x^2y^2\)
5229849
Remove the parentheses and combine like terms. \((7.2u^3v^2-4.1uv^3+2.5w)-(3.8u^3v^2+1.9uv^3-0.4w)+(1.5uv^3-3.2w)\)

Hints

- Check every sign carefully when removing the subtraction parentheses. - Group terms with exactly the same variable part. - Combine the coefficients of each group separately.

Solution

1. Remove the parentheses, reversing the signs in the polynomial being subtracted: \(7.2u^3v^2-4.1uv^3+2.5w-3.8u^3v^2-1.9uv^3+0.4w+1.5uv^3-3.2w\). 2. Combine the \(u^3v^2\) terms: \((7.2-3.8)u^3v^2=3.4u^3v^2\). 3. Combine the \(uv^3\) terms: \((-4.1-1.9+1.5)uv^3=-4.5uv^3\). 4. Combine the \(w\) terms: \((2.5+0.4-3.2)w=-0.3w\). 5. The result is \(3.4u^3v^2-4.5uv^3-0.3w\).

Answer

\(3.4u^3v^2-4.5uv^3-0.3w\)
5229919
Let \(A=4x^2-7y+2\), \(B=-2x^2+3y-5\), and \(C=x^2-y+1\). Simplify each expression. 1) \(A+B+C\) 2) \(A-B-C\)

Hints

- Group terms with the same variable part. - Reverse every sign in an expression being subtracted. - Only terms with identical variables and exponents are like terms. - Combine the constant terms separately.

Solution

1. Substitute the expressions: \((4x^2-7y+2)+(-2x^2+3y-5)+(x^2-y+1)\). Combine like terms: \((4-2+1)x^2+(-7+3-1)y+(2-5+1)=3x^2-5y-2\). 2. Substitute the expressions: \((4x^2-7y+2)-(-2x^2+3y-5)-(x^2-y+1)\). Remove the subtraction parentheses: \(4x^2-7y+2+2x^2-3y+5-x^2+y-1\). Combine like terms: \((4+2-1)x^2+(-7-3+1)y+(2+5-1)=5x^2-9y+6\).

Answer

1) \(3x^2-5y-2\) 2) \(5x^2-9y+6\)
5229999
Let \(A=4.5x^2-5x+7\), \(B=-2.5x^2+3x-4\), and \(C=x^2-1.5x+2\). Simplify each expression. a) \(A+B+C\) b) \(A-(B+C)\)

Hints

- Group terms with identical variables and exponents. - Reverse every sign in an expression being subtracted. - Simplify the expression inside parentheses before subtracting it.

Solution

1. For part a, substitute and combine like terms: \((4.5-2.5+1)x^2+(-5+3-1.5)x+(7-4+2)=3x^2-3.5x+5\). 2. For part b, first find \(B+C=(-2.5+1)x^2+(3-1.5)x+(-4+2)=-1.5x^2+1.5x-2\). 3. Subtract this expression from \(A\): \((4.5x^2-5x+7)-(-1.5x^2+1.5x-2)\). 4. Remove the parentheses and combine like terms: \(4.5x^2+1.5x^2-5x-1.5x+7+2=6x^2-6.5x+9\).

Answer

a) \(3x^2-3.5x+5\) b) \(6x^2-6.5x+9\)
5230539
Expand and simplify. 1) \(7x(2x - 3y)\) 2) \(-3a(4b + 2a)\) 3) \(0.4z(10z - 5)\)

Hints

- Multiply the monomial by every term in the parentheses. - Pay close attention to signs when the monomial is negative. - Remember that \(x \cdot x = x^2\).

Solution

1. \(7x(2x - 3y) = 14x^2 - 21xy\). 2. \(-3a(4b + 2a) = -12ab - 6a^2\). 3. \(0.4z(10z - 5) = 4z^2 - 2z\).

Answer

1) \(14x^2 - 21xy\) 2) \(-12ab - 6a^2\) 3) \(4z^2 - 2z\)
5230559
Use the distributive property to expand. 1) \(9(3x - 5y)\) 2) \(-4(2a + 6b - 3)\) 3) \(2m(4n - 7p)\)

Hints

- Multiply the factor outside the parentheses by every term inside. - Pay close attention to signs when the outside factor is negative. - Multiply both the numerical coefficients and the variable factors.

Solution

1. \(9(3x - 5y) = 27x - 45y\). 2. \(-4(2a + 6b - 3) = -8a - 24b + 12\). 3. \(2m(4n - 7p) = 8mn - 14mp\).

Answer

1) \(27x - 45y\) 2) \(-8a - 24b + 12\) 3) \(8mn - 14mp\)
5230579
Expand each expression. a) \(5a(2a^2 - 3a + 4)\) b) \(-2x^2(3x - 5)\) c) \((4y^2 - y - 6)(-3y)\)

Hints

- Multiply the monomial by every term in the polynomial. - Pay close attention to signs when the monomial is negative. - When multiplying powers with the same base, add their exponents.

Solution

1. For a), \(5a(2a^2 - 3a + 4) = 10a^3 - 15a^2 + 20a\). 2. For b), \(-2x^2(3x - 5) = -6x^3 + 10x^2\). 3. For c), \((4y^2 - y - 6)(-3y) = -12y^3 + 3y^2 + 18y\).

Answer

a) \(10a^3 - 15a^2 + 20a\) b) \(-6x^3 + 10x^2\) c) \(-12y^3 + 3y^2 + 18y\)
5230599
Expand each expression. 1) \(5x(3x^2 - 2xy + 4y^2)\) 2) \(-4ab(2a - 5b - 1)\) 3) \(\frac{1}{2}m(4m^2 + 8mn - 6n^2)\)

Hints

- Multiply the outside monomial by every term inside the parentheses. - Pay close attention to signs when multiplying by a negative monomial. - Add exponents when multiplying powers with the same base. - Writing each partial product can prevent errors.

Solution

1. \(5x(3x^2 - 2xy + 4y^2) = 15x^3 - 10x^2y + 20xy^2\). 2. \(-4ab(2a - 5b - 1) = -8a^2b + 20ab^2 + 4ab\). 3. \(\frac{1}{2}m(4m^2 + 8mn - 6n^2) = 2m^3 + 4m^2n - 3mn^2\).

Answer

1) \(15x^3 - 10x^2y + 20xy^2\) 2) \(-8a^2b + 20ab^2 + 4ab\) 3) \(2m^3 + 4m^2n - 3mn^2\)
5230639
Expand and simplify. 1) \(5x(3x^2 - 4x + 2)\) 2) \(-2ab(4a^2 - 3ab + b^2)\)

Hints

- Multiply the outside monomial by every term in the polynomial. - Pay close attention to signs when multiplying by a negative monomial. - Add exponents when multiplying powers with the same base.

Solution

1. \(5x(3x^2 - 4x + 2) = 15x^3 - 20x^2 + 10x\). 2. \(-2ab(4a^2 - 3ab + b^2) = -8a^3b + 6a^2b^2 - 2ab^3\).

Answer

1) \(15x^3 - 20x^2 + 10x\) 2) \(-8a^3b + 6a^2b^2 - 2ab^3\)
5230719
Expand and simplify. \(-1.5a(4a^2 - 2a + 0.8)\)

Hints

- Multiply the monomial by every term in the polynomial. - Pay close attention to signs when multiplying by a negative number. - Add exponents when multiplying powers with the same base. - Break the work into three separate products.

Solution

1. Distribute \(-1.5a\): \(-1.5a(4a^2 - 2a + 0.8) = -6a^3 + 3a^2 - 1.2a\).

Answer

\(-6a^3 + 3a^2 - 1.2a\)
5230939
Expand and simplify. 1) \((x + 7)(x - 2)\) 2) \((3a - 4)(2a + 5)\) 3) \((5 - 2b)(b + 3)\)

Hints

- Multiply every term in the first binomial by every term in the second. - Check signs carefully. - Combine terms only when their variable parts and exponents match.

Solution

1. \((x + 7)(x - 2) = x^2 - 2x + 7x - 14 = x^2 + 5x - 14\). 2. \((3a - 4)(2a + 5) = 6a^2 + 15a - 8a - 20 = 6a^2 + 7a - 20\). 3. \((5 - 2b)(b + 3) = 5b + 15 - 2b^2 - 6b = -2b^2 - b + 15\).

Answer

1) \(x^2 + 5x - 14\) 2) \(6a^2 + 7a - 20\) 3) \(-2b^2 - b + 15\)
5230979
Expand and simplify. 1) \((x + 8)(x - 2)\) 2) \((a - 4)(b + 5)\) 3) \((y - 3)(y - 6)\)

Hints

- Multiply every term in the first binomial by every term in the second. - Pay close attention to the signs of products involving negative terms. - Combine like terms after expanding.

Solution

1. \((x + 8)(x - 2) = x^2 - 2x + 8x - 16 = x^2 + 6x - 16\). 2. \((a - 4)(b + 5) = ab + 5a - 4b - 20\). 3. \((y - 3)(y - 6) = y^2 - 6y - 3y + 18 = y^2 - 9y + 18\).

Answer

1) \(x^2 + 6x - 16\) 2) \(ab + 5a - 4b - 20\) 3) \(y^2 - 9y + 18\)
5230999
Expand and simplify. 1) \((4x + 3)(2x - 5)\) 2) \((a - 6b)(2a + b)\) 3) \((y^2 + 3)(y^2 - 4)\)

Hints

- Multiply every term in one factor by every term in the other. - Apply the sign rules carefully. - Combine terms only when their variables and exponents match exactly.

Solution

1. \((4x + 3)(2x - 5) = 8x^2 - 20x + 6x - 15 = 8x^2 - 14x - 15\). 2. \((a - 6b)(2a + b) = 2a^2 + ab - 12ab - 6b^2 = 2a^2 - 11ab - 6b^2\). 3. \((y^2 + 3)(y^2 - 4) = y^4 - 4y^2 + 3y^2 - 12 = y^4 - y^2 - 12\).

Answer

1) \(8x^2 - 14x - 15\) 2) \(2a^2 - 11ab - 6b^2\) 3) \(y^4 - y^2 - 12\)
5233599
Divide and simplify. 1) \((15b^3 - 10b^2 + 5b) \div 2.5\) 2) \((-12a^4 + 8a^3 - 4a^2) \div (-4a^2)\), where \(a \ne 0\)

Hints

- Divide every term in the polynomial by the divisor. - Subtract exponents when dividing powers with the same nonzero base. - Apply the sign rules carefully.

Solution

1. Divide each term by \(2.5\): \(15b^3 \div 2.5 = 6b^3\), \(-10b^2 \div 2.5 = -4b^2\), and \(5b \div 2.5 = 2b\). The result is \(6b^3 - 4b^2 + 2b\). 2. Divide each term by \(-4a^2\): \(3a^2\), \(-2a\), and \(1\). The result is \(3a^2 - 2a + 1\).

Answer

1) \(6b^3 - 4b^2 + 2b\) 2) \(3a^2 - 2a + 1\)
5233609
Divide and simplify. 1) \((-12z^6 + 18z^4 - 6z^2) \div \left(\frac{6}{5}z^2\right)\), where \(z \ne 0\) 2) \(\left(\frac{3}{4}x^3 - \frac{1}{2}x^2 + x\right) \div \left(-\frac{1}{4}x\right)\), where \(x \ne 0\)

Hints

- Dividing by a fraction is equivalent to multiplying by its reciprocal. - Divide every term by the monomial. - Subtract exponents on the common variable base.

Solution

1. Divide each coefficient by \(\frac{6}{5}\) and subtract \(2\) from each exponent of \(z\): \(-10z^4 + 15z^2 - 5\). 2. Divide each coefficient by \(-\frac{1}{4}\) and subtract \(1\) from each exponent of \(x\): \(-3x^2 + 2x - 4\).

Answer

1) \(-10z^4 + 15z^2 - 5\) 2) \(-3x^2 + 2x - 4\)
5233669
Divide and simplify. Assume \(a \ne 0\). \((-12a^3 + 18a^2 - 6a) \div (-6a)\)

Hints

- Divide each term separately. - A variable with no written exponent has exponent \(1\). - Check by multiplying your result by the divisor.

Solution

1. Divide each term by \(-6a\): \(-12a^3 \div (-6a) = 2a^2\), \(18a^2 \div (-6a) = -3a\), and \(-6a \div (-6a) = 1\). 2. The result is \(2a^2 - 3a + 1\).

Answer

\(2a^2 - 3a + 1\)
5233699
Divide and simplify. Assume \(a \ne 0\) and \(b \ne 0\). \((12a^3b^2 + 6a^2b^3 - 3ab^4) \div 3ab^2\)

Hints

- Divide every term in the polynomial by the monomial. - Subtract exponents for each common variable base. - Track the sign of each term.

Solution

1. Divide the first term: \(12a^3b^2 \div 3ab^2 = 4a^2\). 2. Divide the second term: \(6a^2b^3 \div 3ab^2 = 2ab\). 3. Divide the third term: \(-3ab^4 \div 3ab^2 = -b^2\). 4. The result is \(4a^2 + 2ab - b^2\).

Answer

\(4a^2 + 2ab - b^2\)
5233749
Divide and simplify. Assume \(p \ne 0\). \((p^5 - 2.5p^4 + 0.5p^3) \div (-0.5p^2)\)

Hints

- Divide each term by the monomial. - Subtract exponents when dividing powers with the same nonzero base. - Account for the negative divisor in every term.

Solution

1. Divide each coefficient by \(-0.5\): \(-2\), \(5\), and \(-1\). 2. Subtract \(2\) from each exponent of \(p\): \(p^3\), \(p^2\), and \(p\). 3. The result is \(-2p^3 + 5p^2 - p\).

Answer

\(-2p^3 + 5p^2 - p\)
5233839
Divide and simplify. Assume \(x \ne 0\) and \(y \ne 0\). \(\left(6x^4y^3 - \frac{3}{4}x^3y^2 + \frac{1}{2}x^2y^4\right) \div \left(\frac{3}{2}x^2y\right)\)

Hints

- Divide each term in the polynomial by the monomial. - Multiply by the reciprocal when dividing fractional coefficients. - Subtract exponents for each common base.

Solution

1. \(6x^4y^3 \div \left(\frac{3}{2}x^2y\right) = 4x^2y^2\). 2. \(-\frac{3}{4}x^3y^2 \div \left(\frac{3}{2}x^2y\right) = -\frac{1}{2}xy\). 3. \(\frac{1}{2}x^2y^4 \div \left(\frac{3}{2}x^2y\right) = \frac{1}{3}y^3\). 4. The result is \(4x^2y^2 - \frac{1}{2}xy + \frac{1}{3}y^3\).

Answer

\(4x^2y^2 - \frac{1}{2}xy + \frac{1}{3}y^3\)
5233959
Divide and simplify. Assume \(a \ne 0\) and \(b \ne 0\). \((12a^2b - 18ab^2 + 6ab) \div \left(\frac{6}{5}ab\right)\)

Hints

- Divide every term by the monomial. - Dividing by a fraction is multiplying by its reciprocal. - Cancel common nonzero variable factors.

Solution

1. Divide the first term: \(12a^2b \div \left(\frac{6}{5}ab\right) = 10a\). 2. Divide the second term: \(-18ab^2 \div \left(\frac{6}{5}ab\right) = -15b\). 3. Divide the third term: \(6ab \div \left(\frac{6}{5}ab\right) = 5\). 4. The result is \(10a - 15b + 5\).

Answer

\(10a - 15b + 5\)
5244399
Combine like terms. \(9x^2-5xy+3y^2-12x^2+5xy-2y^2\)

Hints

- Group terms with exactly the same variables and exponents. - Include the sign attached to each coefficient. - Opposite terms cancel.

Solution

1. Combine the \(x^2\) terms: \(9x^2-12x^2=-3x^2\). 2. Combine the \(xy\) terms: \(-5xy+5xy=0\). 3. Combine the \(y^2\) terms: \(3y^2-2y^2=y^2\). 4. The simplified expression is \(-3x^2+y^2\).

Answer

\(-3x^2+y^2\)
5244409
Combine like terms. \(3.5a^2b-2ab^2+\frac{1}{2}a^2b+4ab^2-7\)

Hints

- Distinguish between \(a^2b\) and \(ab^2\); they are not like terms. - Express \(\frac{1}{2}\) as a decimal to combine it with \(3.5\). - Keep the constant term in the final expression.

Solution

1. The \(a^2b\) terms are like terms. Since \(\frac{1}{2}=0.5\), their coefficients have sum \(3.5+0.5=4\). 2. The \(ab^2\) terms are like terms, and their coefficients have sum \(-2+4=2\). 3. The constant \(-7\) has no like term. 4. The simplified expression is \(4a^2b+2ab^2-7\).

Answer

\(4a^2b+2ab^2-7\)
5244419
Combine like terms. \(2.4x^2-1.5xy+0.8x^2-3.2y^2+0.15xy\)

Hints

- Identify terms with exactly the same variables and exponents. - Group like terms before adding their coefficients. - Include the sign attached to each coefficient. - Combine only the numerical coefficients.

Solution

1. Combine the \(x^2\) terms: \((2.4+0.8)x^2=3.2x^2\). 2. Combine the \(xy\) terms: \((-1.5+0.15)xy=-1.35xy\). 3. The term \(-3.2y^2\) has no like term. 4. The simplified expression is \(3.2x^2-1.35xy-3.2y^2\).

Answer

\(3.2x^2-1.35xy-3.2y^2\)
5244429
Combine like terms. \(a^2b-0.4ab^2+1.2a^2b-0.75+0.15ab^2\)

Hints

- Compare the exponents carefully; \(a^2b\) and \(ab^2\) are not like terms. - A term with no written coefficient has coefficient \(1\). - Group terms with identical variable parts. - Keep constants separate from variable terms.

Solution

1. The \(a^2b\) terms are like terms. Their coefficients have sum \(1+1.2=2.2\). 2. The \(ab^2\) terms are like terms. Their coefficients have sum \(-0.4+0.15=-0.25\). 3. The constant \(-0.75\) has no like term. 4. The simplified expression is \(2.2a^2b-0.25ab^2-0.75\).

Answer

\(2.2a^2b-0.25ab^2-0.75\)
5244459
Combine like terms. \(12x^3-7x^2+4x-5x^3+7x^2-9\)

Hints

- Group terms with exactly the same variable and exponent. - Include the sign attached to each coefficient. - Opposite terms cancel. - Arrange like terms next to one another before combining them.

Solution

1. Combine the \(x^3\) terms: \(12x^3-5x^3=7x^3\). 2. Combine the \(x^2\) terms: \(-7x^2+7x^2=0\). 3. The terms \(4x\) and \(-9\) have no like terms. 4. The simplified expression is \(7x^3+4x-9\).

Answer

\(7x^3+4x-9\)
5244469
Determine whether \(T_1\) and \(T_2\) are equivalent. Justify your answer by simplifying. \(T_1=6b^2-4b+3-2b^2+5b-8\) \(T_2=4b^2+b-5\)

Hints

- Equivalent expressions have the same value for every allowed value of the variable. - Simplify the more complicated expression first. - Group all \(b^2\) terms, all \(b\) terms, and all constants. - Compare the simplified result with \(T_2\).

Solution

1. Combine the \(b^2\) terms in \(T_1\): \(6b^2-2b^2=4b^2\). 2. Combine the \(b\) terms: \(-4b+5b=b\). 3. Combine the constants: \(3-8=-5\). 4. Therefore, \(T_1=4b^2+b-5\), which is identical to \(T_2\). 5. The expressions are equivalent because they have the same value for every value of \(b\).

Answer

Yes. Simplifying \(T_1\) gives \(4b^2+b-5\), which is identical to \(T_2\).
5279379
Rewrite repeated products using exponents, then combine like terms. 1) \(k \cdot k + k \cdot k + k \cdot k\) 2) \(x \cdot x \cdot x + y \cdot y + x \cdot x \cdot x + y \cdot y\) 3) \(a^2 + a \cdot a + a^2\) 4) \(m \cdot m \cdot m + n \cdot n + m^3\)

Hints

- Rewrite each repeated product as a power. - Combine only terms with identical variable parts. - Count how many copies of each like term appear.

Solution

1. \(k^2 + k^2 + k^2 = 3k^2\). 2. \(x^3 + y^2 + x^3 + y^2 = 2x^3 + 2y^2\). 3. \(a^2 + a^2 + a^2 = 3a^2\). 4. \(m^3 + n^2 + m^3 = 2m^3 + n^2\).

Answer

1) \(3k^2\) 2) \(2x^3 + 2y^2\) 3) \(3a^2\) 4) \(2m^3 + n^2\)
5279539
Combine like terms. \(9x^2+(-4y)+(-5x^2)+(+4y)+(-3x^2)\)

Hints

- Group terms with the same variables and exponents. - Adding a negative term is the same as subtracting it. - Combine the coefficients of each group separately. - A term with coefficient \(0\) disappears.

Solution

1. Combine the \(x^2\) terms: \((9-5-3)x^2=x^2\). 2. Combine the \(y\) terms: \((-4+4)y=0\). 3. The simplified expression is \(x^2\).

Answer

\(x^2\)
5279549
Combine like terms. \(1.8ab+(-0.6a^2)+(-0.8ab)+(-1.4a^2)+2a^2\)

Hints

- Combine only terms with exactly the same variable part. - Track the signs when adding decimal coefficients. - The terms \(ab\) and \(a^2\) are not like terms. - A group whose coefficients sum to \(0\) disappears.

Solution

1. Combine the \(ab\) terms: \((1.8-0.8)ab=ab\). 2. Combine the \(a^2\) terms: \((-0.6-1.4+2)a^2=0\). 3. The simplified expression is \(ab\).

Answer

\(ab\)
5279559
Remove the parentheses and combine like terms. a) \((8x+12y)-(5x-3y)\) b) \((4a^2-7a)-(a^2+2a)\) c) \((9uv+4v)-(9uv-6v)\) d) \(-(3k-5)+(7k-2)\)

Hints

- Reverse every sign in an expression being subtracted. - Combine only terms with exactly the same variable part. - Distinguish variable terms from terms with powers, such as \(a\) and \(a^2\). - Group like terms before combining their coefficients.

Solution

1. For part a, remove the parentheses and combine like terms: \(8x+12y-5x+3y=3x+15y\). 2. For part b, remove the parentheses and combine like terms: \(4a^2-7a-a^2-2a=3a^2-9a\). 3. For part c, remove the parentheses and combine like terms: \(9uv+4v-9uv+6v=10v\). 4. For part d, remove the parentheses and combine like terms: \(-3k+5+7k-2=4k+3\).

Answer

a) \(3x+15y\) b) \(3a^2-9a\) c) \(10v\) d) \(4k+3\)
5279879
Simplify each quotient. Assume each divisor is nonzero. a) \((12x^2y - 8xy + 4y) \div 4y\), where \(y \ne 0\) b) \((-15a^3b^2 + 10a^2b - 5ab) \div (-5ab)\), where \(ab \ne 0\)

Hints

- Rewrite division as multiplication by a reciprocal if helpful. - Divide every term in the numerator by the divisor. - Track signs carefully when dividing by a negative expression. - Apply the quotient rule for exponents.

Solution

1. a) Divide each term by \(4y\): \(12x^2y \div 4y = 3x^2\), \(-8xy \div 4y = -2x\), and \(4y \div 4y = 1\). The result is \(3x^2 - 2x + 1\). 2. b) Divide each term by \(-5ab\): \(-15a^3b^2 \div (-5ab) = 3a^2b\), \(10a^2b \div (-5ab) = -2a\), and \(-5ab \div (-5ab) = 1\). The result is \(3a^2b - 2a + 1\).

Answer

a) \(3x^2 - 2x + 1\) b) \(3a^2b - 2a + 1\)
5290539
Determine whether each function is a polynomial function. If it is, rewrite it in standard polynomial form. a) \(f_1(x)=\frac{x^5-10}{5}\) b) \(f_2(x)=x^{\frac{1}{2}}\) c) \(f_3(x)=(2x+3)^2\) d) \(f_4(x)=\frac{3}{x}+x\) e) \(f_5(x)=\sqrt{7}x^3\)

Hints

- Check whether every exponent of \(x\) is a nonnegative integer. - Rewrite divisions and radicals involving \(x\) as powers when helpful. - Polynomial coefficients may be fractions or irrational real numbers. - Expand products to reveal standard polynomial form.

Solution

1. A polynomial function has real coefficients and only nonnegative integer exponents of \(x\). 2. For a), \(f_1(x)=\frac{1}{5}x^5-2\), so it is a polynomial. 3. For b), the exponent \(\frac{1}{2}\) is not a nonnegative integer, so it is not a polynomial. 4. For c), \((2x+3)^2=4x^2+12x+9\), so it is a polynomial. 5. For d), \(\frac{3}{x}=3x^{-1}\) has a negative exponent, so it is not a polynomial. 6. For e), \(\sqrt{7}\) is a real coefficient and the exponent \(3\) is a nonnegative integer, so it is a polynomial.

Answer

a) Yes: \(f_1(x)=\frac{1}{5}x^5-2\) b) No c) Yes: \(f_3(x)=4x^2+12x+9\) d) No e) Yes: \(f_5(x)=\sqrt{7}x^3\)
5125639
A square flower bed and a rectangular vegetable bed have the same area. The rectangle is \(4\,\text{ft}\) longer than the side of the square and \(3\,\text{ft}\) narrower than the side of the square. Find the side length of the square bed.

Hints

- Represent the square's side length with a variable. - Express both rectangle dimensions using that variable. - Set the two area expressions equal. - Expand the product and check whether the quadratic terms cancel.

Solution

1. Let \(s\) feet be the side length of the square. Its area is \(s^2\). 2. The rectangle has dimensions \(s + 4\) and \(s - 3\), so its area is \((s + 4)(s - 3)\). 3. Set the areas equal: \(s^2 = (s + 4)(s - 3)\). 4. Expand the product: \(s^2 = s^2 + s - 12\). 5. Subtract \(s^2\) from both sides: \(0 = s - 12\), so \(s = 12\).

Answer

The square bed has side length \(12\,\text{ft}\).
5132949
Simplify each expression. a) \(9a - (4a - 7b) - 2b\) b) \(4x(3 - y) + 4xy - 10x\)

Hints

- Remove parentheses before combining terms. - Combine only like terms. - Check the signs carefully, especially when subtracting parentheses.

Solution

1. For a), remove the parentheses and combine like terms: \(9a - 4a + 7b - 2b = 5a + 5b\). 2. For b), distribute and combine like terms: \(4x(3 - y) + 4xy - 10x = 12x - 4xy + 4xy - 10x = 2x\).

Answer

a) \(5a + 5b\) b) \(2x\)
5137149
Expand and combine like terms. a) \(15x - 4y + 10 - (6x + 2y - 3)\) b) \(4.2a^2 - (2a - 1.8a^2) + 5a\) c) \(12 - 3(x - 4) + 2(5 - 2x)\)

Hints

- When subtracting parentheses, change the sign of every term inside. - Identify like terms by matching both their variables and exponents. - Expand all products before combining terms. - A negative factor times a negative term gives a positive term.

Solution

1. For a), \(15x - 4y + 10 - 6x - 2y + 3 = 9x - 6y + 13\). 2. For b), \(4.2a^2 - 2a + 1.8a^2 + 5a = 6a^2 + 3a\). 3. For c), \(12 - 3x + 12 + 10 - 4x = 34 - 7x\).

Answer

a) \(9x - 6y + 13\) b) \(6a^2 + 3a\) c) \(34 - 7x\)
5137159
Simplify each expression. a) \(\frac{2}{5}m + \frac{3}{4}n - \left(\frac{1}{10}m - \frac{1}{2}n\right)\) b) \(4a(3b) - 2a(b + 5) + ab\) c) \(x^2 - \left[4x - (2x^2 + x)\right] + 7\)

Hints

- Use common denominators before adding or subtracting fractional coefficients. - With nested grouping symbols, work from the inside out. - Products such as \(ab\) are like terms only with other terms having exactly the same variable factors.

Solution

1. For a), remove the parentheses and combine like terms: \(\left(\frac{2}{5} - \frac{1}{10}\right)m + \left(\frac{3}{4} + \frac{1}{2}\right)n = \frac{3}{10}m + \frac{5}{4}n\). 2. For b), expand and combine like terms: \(12ab - 2ab - 10a + ab = 11ab - 10a\). 3. For c), work from the inside out: \(x^2 - (4x - 2x^2 - x) + 7 = x^2 - 3x + 2x^2 + 7 = 3x^2 - 3x + 7\).

Answer

a) \(\frac{3}{10}m + \frac{5}{4}n\) b) \(11ab - 10a\) c) \(3x^2 - 3x + 7\)
5139219
Simplify \(3a(2a - 5) - (a - 4)(a + 4)\).

Hints

- Simplify each product before subtracting. - Recognize the conjugate product \((a - 4)(a + 4)\). - Distribute the negative sign across the second result.

Solution

1. Distribute: \(3a(2a - 5) = 6a^2 - 15a\). 2. Use the difference of squares: \((a - 4)(a + 4) = a^2 - 16\). 3. Subtract and combine like terms: \(6a^2 - 15a - (a^2 - 16) = 5a^2 - 15a + 16\).

Answer

\(5a^2 - 15a + 16\)
5139229
Expand and simplify \((x - 5)^2 - (x + 2)^2\).

Hints

- Expand both binomial squares. - Apply the subtraction sign to every term in the second polynomial. - Combine like terms.

Solution

1. Expand the first square: \((x - 5)^2 = x^2 - 10x + 25\). 2. Expand the second square: \((x + 2)^2 = x^2 + 4x + 4\). 3. Subtract: \(x^2 - 10x + 25 - x^2 - 4x - 4 = -14x + 21\).

Answer

\(-14x + 21\)
5142929
Expand and simplify each expression. a) \((2x + 5)^2 - (2x - 5)^2\) b) \((3y - 2)^2 + (3y + 2)(3y - 2)\)

Hints

- Expand each binomial expression separately. - Apply the subtraction sign to every term in part a). - Combine like terms after expansion.

Solution

1. a) Expand both squares: \(4x^2 + 20x + 25 - (4x^2 - 20x + 25) = 40x\). 2. b) Expand the square and use the difference of squares: \(9y^2 - 12y + 4 + 9y^2 - 4 = 18y^2 - 12y\).

Answer

a) \(40x\) b) \(18y^2 - 12y\)
5152219
Simplify each expression completely. Pay attention to exponents and to equivalent variable products. a) \(4x^2y-2xy^2+3yx^2-5y^2x\) b) \(\frac{3}{4}ab-\frac{1}{2}ba+2.5ab\) c) \(z(2z-3)-(z^2+4z)\)

Hints

- Products such as \(x^2y\) and \(yx^2\) have the same variable part. - Express fractions and decimals in a common form before combining coefficients. - Distribute carefully in part c, including the negative sign before the second set of parentheses.

Solution

1. For part a, use the commutative property to recognize \(yx^2=x^2y\) and \(y^2x=xy^2\). Then combine like terms: \(4x^2y+3x^2y-2xy^2-5xy^2=7x^2y-7xy^2\). 2. For part b, \(ba=ab\). Combine the coefficients: \(\frac{3}{4}-\frac{1}{2}+2.5=0.75-0.5+2.5=2.75\). The result is \(2.75ab\), or \(\frac{11}{4}ab\). 3. For part c, distribute and remove the parentheses: \(z(2z-3)-(z^2+4z)=2z^2-3z-z^2-4z=z^2-7z\).

Answer

a) \(7x^2y-7xy^2\) b) \(2.75ab\), or \(\frac{11}{4}ab\) c) \(z^2-7z\)
5152229
Expand and simplify. a) \(5r(s - 2) - 3s(r + 4) + 10r\) b) \(\frac{1}{3}x(6x - 9y) - (x^2 - 2xy)\) c) \(k^2m - k(km - k) + m\)

Hints

- Distribute the factor outside parentheses to every term inside. - Pay close attention when a product or set of parentheses is subtracted. - Look for terms that cancel.

Solution

1. For a), \(5rs - 10r - 3rs - 12s + 10r = 2rs - 12s\). 2. For b), \(2x^2 - 3xy - x^2 + 2xy = x^2 - xy\). 3. For c), \(k^2m - (k^2m - k^2) + m = k^2m - k^2m + k^2 + m = k^2 + m\).

Answer

a) \(2rs - 12s\) b) \(x^2 - xy\) c) \(k^2 + m\)
5152359
Use binomial identities to simplify each expression. a) \((x + 4)^2 - (x - 4)^2\) b) \((2a + 3)(2a - 3) + (a + 3)^2\)

Hints

- Identify the binomial identity for each product or square. - Distribute the subtraction sign in part a). - Combine like terms after expansion.

Solution

1. a) Expand both squares: \(x^2 + 8x + 16 - (x^2 - 8x + 16) = 16x\). 2. b) Use the difference of squares and expand the binomial square: \(4a^2 - 9 + a^2 + 6a + 9 = 5a^2 + 6a\).

Answer

a) \(16x\) b) \(5a^2 + 6a\)
5152369
Expand and simplify each expression completely. a) \((k - 0.5)^2 + k(1 - k)\) b) \(\left(\frac{1}{2}x + 4\right)^2 - \frac{1}{4}(x - 2)(x + 2)\)

Hints

- Expand each component before combining them. - Apply the factor \(\frac{1}{4}\) to both terms in the product result. - Combine like terms at the end.

Solution

1. a) \((k - 0.5)^2 = k^2 - k + 0.25\), and \(k(1 - k) = k - k^2\). Their sum is \(0.25\). 2. b) The square is \(\frac{1}{4}x^2 + 4x + 16\), and \((x - 2)(x + 2) = x^2 - 4\). Therefore, \(\frac{1}{4}x^2 + 4x + 16 - \frac{1}{4}(x^2 - 4) = 4x + 17\).

Answer

a) \(0.25\) b) \(4x + 17\)
5152379
Use binomial identities and the distributive property to simplify each expression completely. a) \((a + b)^2 - (a - b)^2 - (2a + b)(2a - b) + 4a^2\) b) \(3(x - 2)^2 - 2(x - 3)(x + 3) - x^2\)

Hints

- Simplify each major product or square separately. - Apply factors outside parentheses to every term. - Look for terms that cancel.

Solution

1. a) The difference of the first two squares is \(4ab\). Also, \(-(2a + b)(2a - b) = -(4a^2 - b^2)\). Combining with \(4a^2\) gives \(4ab + b^2\). 2. b) Expand: \(3(x^2 - 4x + 4) - 2(x^2 - 9) - x^2\). Combining like terms gives \(-12x + 30\).

Answer

a) \(4ab + b^2\) b) \(-12x + 30\)
5152869
Expand each product and simplify. a) \(2x^3(4x^2 - 5x + 1)\) b) \(-ab^2(3a^2b - 2b + 7)\) c) \(4s^2t^3(s^2 - 3st + 2t^2)\)

Hints

- When multiplying powers with the same base, add the exponents. - Pay close attention to the sign when the outside factor is negative. - Multiply the outside monomial by every term in the polynomial.

Solution

1. For a), distribute and add exponents of like bases: \(2x^3(4x^2 - 5x + 1) = 8x^5 - 10x^4 + 2x^3\). 2. For b), \(-ab^2(3a^2b - 2b + 7) = -3a^3b^3 + 2ab^3 - 7ab^2\). 3. For c), \(4s^2t^3(s^2 - 3st + 2t^2) = 4s^4t^3 - 12s^3t^4 + 8s^2t^5\).

Answer

a) \(8x^5 - 10x^4 + 2x^3\) b) \(-3a^3b^3 + 2ab^3 - 7ab^2\) c) \(4s^4t^3 - 12s^3t^4 + 8s^2t^5\)
5154809
Simplify the polynomial. \(\frac{2}{3}a^3-0.75a^2+\frac{1}{6}a^3+\frac{1}{4}a^2-a^3\)

Hints

- An \(a^3\)-term with no visible coefficient has coefficient \(1\). - Convert fractions and decimals to a common form. - Combine terms only when their variable parts and exponents match.

Solution

1. Combine the \(a^3\)-terms: \(\frac{2}{3}+\frac{1}{6}-1=\frac{4}{6}+\frac{1}{6}-\frac{6}{6}=-\frac{1}{6}\). 2. Combine the \(a^2\)-terms: \(-0.75+\frac{1}{4}=-0.75+0.25=-0.5\). 3. The simplified polynomial is \(-\frac{1}{6}a^3-0.5a^2\).

Answer

\(-\frac{1}{6}a^3-0.5a^2\)
5154849
Expand and simplify \((3a + 2)^2 - (3a - 2)^2\).

Hints

- Expand both binomial squares. - Distribute the subtraction sign across the second polynomial. - Identify terms that cancel.

Solution

1. \((3a + 2)^2 = 9a^2 + 12a + 4\). 2. \((3a - 2)^2 = 9a^2 - 12a + 4\). 3. Subtracting gives \(9a^2 + 12a + 4 - 9a^2 + 12a - 4 = 24a\).

Answer

\(24a\)
5154859
Simplify \(2(x + 5)(x - 5) - (x - 3)^2\).

Hints

- Simplify the conjugate product first. - Expand the binomial square separately. - Apply the subtraction sign before combining like terms.

Solution

1. Use the difference of squares: \((x + 5)(x - 5) = x^2 - 25\), so the first part is \(2x^2 - 50\). 2. Expand \((x - 3)^2 = x^2 - 6x + 9\). 3. Subtract and combine: \(2x^2 - 50 - x^2 + 6x - 9 = x^2 + 6x - 59\).

Answer

\(x^2 + 6x - 59\)
5154869
Simplify \(\frac{1}{2}(2z + 4)^2 - (z - 1)(z + 1)\).

Hints

- Expand the square before applying the outside factor. - Recognize the conjugate product in the second term. - Distribute the subtraction sign carefully.

Solution

1. Expand the square: \((2z + 4)^2 = 4z^2 + 16z + 16\). Multiplying by \(\frac{1}{2}\) gives \(2z^2 + 8z + 8\). 2. Use the difference of squares: \((z - 1)(z + 1) = z^2 - 1\). 3. Subtract: \(2z^2 + 8z + 8 - (z^2 - 1) = z^2 + 8z + 9\).

Answer

\(z^2 + 8z + 9\)
5227569
Combine like terms. \(\frac{2}{5}a^2b+\frac{3}{2}ab^2-0.6a^2b-\frac{3}{4}ab^2+5\)

Hints

- \(a^2b\) and \(ab^2\) are different variable parts. - Express fractional and decimal coefficients in a common form. - Keep the constant term in the final expression.

Solution

1. Combine the \(a^2b\)-terms: \(\frac{2}{5}-0.6=0.4-0.6=-0.2=-\frac{1}{5}\). 2. Combine the \(ab^2\)-terms: \(\frac{3}{2}-\frac{3}{4}=\frac{6}{4}-\frac{3}{4}=\frac{3}{4}\). 3. Keep the constant term \(5\). The result is \(-\frac{1}{5}a^2b+\frac{3}{4}ab^2+5\).

Answer

\(-\frac{1}{5}a^2b+\frac{3}{4}ab^2+5\)
5227689
Find the missing term or coefficient. 1) \(2.5a^3b-\underline{\hspace{1cm}}+1.2a^3b=0.7a^3b\) 2) \(\underline{\hspace{1cm}}x^2y^2+3.4x^2y^2-5x^2y^2=-2.1x^2y^2\)

Hints

- Combine the known like terms first. - Treat the missing value as an unknown in an equation. - Use inverse operations on the coefficients.

Solution

1. Let the missing coefficient be \(k\). The known coefficients add to \(2.5+1.2=3.7\), so \(3.7-k=0.7\). Thus \(k=3\), and the missing term is \(3a^3b\). 2. Let the missing coefficient be \(c\). Combine the known coefficients: \(3.4-5=-1.6\). Then \(c-1.6=-2.1\), so \(c=-0.5\).

Answer

1) \(3a^3b\) 2) \(-0.5\)
5228109
Consider the polynomial \(5x^2-12x+9-8x^2+4x-15\). a) Combine like terms and write the result in descending powers of \(x\). b) Explain why \(x^2\)-terms and \(x\)-terms cannot be combined into one term.

Hints

- Group terms by their powers of \(x\). - Keep each term’s sign. - Like terms must have identical variable parts and exponents.

Solution

1. Combine the quadratic terms: \(5x^2-8x^2=-3x^2\). 2. Combine the linear terms: \(-12x+4x=-8x\). 3. Combine the constants: \(9-15=-6\). 4. In descending powers, the result is \(-3x^2-8x-6\). 5. The variable parts \(x^2\) and \(x\) have different exponents, so they are not like terms and cannot be combined by adding their coefficients.

Answer

a) \(-3x^2-8x-6\) b) \(x^2\)-terms and \(x\)-terms have different exponents, so they are not like terms.
5228249
Determine whether the expressions are equivalent. Simplify Expression A and compare it with Expression B. Expression A: \((-2.4ab)+(+1.5a^2)+(-0.6b)+(+3.1ab)+(-0.5a^2)\) Expression B: \(a^2+0.7ab-0.6b\)

Hints

- Simplify Expression A before comparing. - \(a^2\), \(ab\), and \(b\) are different variable parts. - Compare every coefficient and sign after simplifying.

Solution

1. Combine the \(a^2\)-terms in Expression A: \(1.5a^2-0.5a^2=a^2\). 2. Combine the \(ab\)-terms: \(-2.4ab+3.1ab=0.7ab\). 3. The \(-0.6b\) term remains unchanged. 4. Expression A simplifies to \(a^2+0.7ab-0.6b\), which is identical to Expression B.

Answer

Yes. The expressions are equivalent because Expression A simplifies to \(a^2+0.7ab-0.6b\).
5228509
Let \(T=(-4x^2)+9x+(-2x^2)+(-12x)+7x^2\). a) Simplify \(T\). b) What expression must be added to \(T\) so the result is exactly \(x^2\)?

Hints

- Combine terms with the same powers of \(x\). - Identify the extra term in the simplified expression. - Add its opposite to make it cancel.

Solution

1. Combine the quadratic terms: \(-4x^2-2x^2+7x^2=x^2\). 2. Combine the linear terms: \(9x-12x=-3x\). 3. Therefore, \(T=x^2-3x\). 4. To obtain \(x^2\), add the opposite of \(-3x\), which is \(3x\): \(x^2-3x+3x=x^2\).

Answer

a) \(x^2-3x\) b) \(3x\)
5228609
Convert the fractional coefficients to decimals, then combine like terms. \(1.2x^2-\frac{3}{4}x+0.5-0.8x^2+1\frac{1}{2}x-1.1\)

Hints

- Convert every coefficient to the same numerical form. - \(x^2\)-terms and \(x\)-terms are not like terms. - Combine constants separately.

Solution

1. Convert the coefficients: \(\frac{3}{4}=0.75\) and \(1\frac{1}{2}=1.5\). 2. Combine the \(x^2\)-terms: \(1.2x^2-0.8x^2=0.4x^2\). 3. Combine the \(x\)-terms: \(-0.75x+1.5x=0.75x\). 4. Combine the constants: \(0.5-1.1=-0.6\). 5. The simplified expression is \(0.4x^2+0.75x-0.6\).

Answer

\(0.4x^2+0.75x-0.6\)
5229029
A student added two polynomials and obtained \(5x^2-3x+8\). One of the polynomials was \(2x^2+4x-1\). Find the other polynomial.

Hints

- Subtract the known polynomial from the sum. - Reverse every sign in the polynomial being subtracted. - Combine like terms by degree.

Solution

1. Let the missing polynomial be \(Q\): \((2x^2+4x-1)+Q=5x^2-3x+8\). 2. Subtract the known polynomial: \(Q=(5x^2-3x+8)-(2x^2+4x-1)\). 3. Distribute the negative sign: \(Q=5x^2-3x+8-2x^2-4x+1\). 4. Combine like terms: \(Q=3x^2-7x+9\).

Answer

\(3x^2-7x+9\)
5229299
Solve each equation. a) \((6x - 11) + (4x + 5) = 24\) b) \((2y^2 + 9y - 15) - (2y^2 - y + 5) = 60\) c) \(25 - (8z - 3) + (3z - 2) = 1\)

Hints

- Distribute a subtraction sign to every term in the following parentheses. - Combine like terms before solving. - Check whether the quadratic terms in part b) cancel. - Group variable terms and constants separately.

Solution

1. For a), remove the parentheses and combine like terms: \(10x - 6 = 24\). Add \(6\): \(10x = 30\). Divide by \(10\): \(x = 3\). 2. For b), distribute the subtraction: \(2y^2 + 9y - 15 - 2y^2 + y - 5 = 60\). 3. The quadratic terms cancel, so \(10y - 20 = 60\). Add \(20\): \(10y = 80\). Divide by \(10\): \(y = 8\). 4. For c), distribute the subtraction and remove the parentheses: \(25 - 8z + 3 + 3z - 2 = 1\). 5. Combine like terms: \(-5z + 26 = 1\). Subtract \(26\): \(-5z = -25\). Divide by \(-5\): \(z = 5\).

Answer

a) \(x = 3\) b) \(y = 8\) c) \(z = 5\)
5229569
Let \(P=12x^2+4x-5\) and \(Q=5x^2-2x+7\). a) Find and simplify \(P-Q\). b) Find and simplify \(Q-P\). Compare it with your answer to part a and explain the relationship.

Hints

- Put the entire polynomial being subtracted in parentheses. - Reverse every sign in the second polynomial. - Compare corresponding coefficients in the two results.

Solution

1. \(P-Q=(12x^2+4x-5)-(5x^2-2x+7)\). 2. Distribute the negative sign and combine like terms: \(12x^2+4x-5-5x^2+2x-7=7x^2+6x-12\). 3. \(Q-P=(5x^2-2x+7)-(12x^2+4x-5)\). 4. Simplify: \(5x^2-2x+7-12x^2-4x+5=-7x^2-6x+12\). 5. The second result is the opposite of the first because \(Q-P=-(P-Q)\).

Answer

a) \(7x^2+6x-12\) b) \(-7x^2-6x+12\). It is the opposite of the result in part a.
5229649
Simplify the polynomial. \(\left(2a^3-\frac{5}{8}a^2+\frac{1}{3}a\right)-\left(\frac{3}{4}a^3+a^2-\frac{1}{6}a+1\right)+\left(\frac{1}{2}a^3-\frac{1}{4}\right)\)

Hints

- Distribute the negative sign to every term in the middle polynomial. - Group terms by degree. - Use common denominators for each group of coefficients.

Solution

1. Remove the parentheses: \(2a^3-\frac{5}{8}a^2+\frac{1}{3}a-\frac{3}{4}a^3-a^2+\frac{1}{6}a-1+\frac{1}{2}a^3-\frac{1}{4}\). 2. Combine the cubic terms: \(2-\frac{3}{4}+\frac{1}{2}=\frac{7}{4}\). 3. Combine the quadratic terms: \(-\frac{5}{8}-1=-\frac{13}{8}\). 4. Combine the linear terms: \(\frac{1}{3}+\frac{1}{6}=\frac{1}{2}\). 5. Combine the constants: \(-1-\frac{1}{4}=-\frac{5}{4}\). 6. The simplified polynomial is \(\frac{7}{4}a^3-\frac{13}{8}a^2+\frac{1}{2}a-\frac{5}{4}\).

Answer

\(\frac{7}{4}a^3-\frac{13}{8}a^2+\frac{1}{2}a-\frac{5}{4}\)
5229669
Simplify the expression. \(\frac{1}{2}a^2b-(0.3ab^2-1.5a^2b)+\left(-0.7ab^2+\frac{1}{4}a^2b\right)\)

Hints

- Convert all coefficients to a common form. - \(a^2b\) and \(ab^2\) are not like terms. - Remove the parentheses before combining coefficients.

Solution

1. Convert the fractional coefficients: \(\frac{1}{2}=0.5\) and \(\frac{1}{4}=0.25\). 2. Remove the parentheses: \(0.5a^2b-0.3ab^2+1.5a^2b-0.7ab^2+0.25a^2b\). 3. Combine the \(a^2b\)-terms: \(0.5+1.5+0.25=2.25\). 4. Combine the \(ab^2\)-terms: \(-0.3-0.7=-1\). 5. The simplified expression is \(2.25a^2b-ab^2\).

Answer

\(2.25a^2b-ab^2\)
5229829
Simplify the expression. \(10a^2-\{5a^2-[2a-(3a^2-a)]+4a\}\)

Hints

- Work from the innermost grouping symbols outward. - Pay close attention to each negative sign before a grouped expression. - Treat \(a^2\) terms and \(a\) terms as different kinds of terms. - Combine like terms whenever a grouped expression has been simplified.

Solution

1. Simplify the innermost grouping: \(2a-(3a^2-a)=2a-3a^2+a=3a-3a^2\). 2. Substitute into the expression in braces: \(5a^2-[3a-3a^2]+4a\). 3. Remove the brackets and combine like terms: \(5a^2-3a+3a^2+4a=8a^2+a\). 4. Subtract the expression in braces: \(10a^2-(8a^2+a)=2a^2-a\).

Answer

\(2a^2-a\)
5229889
Write \(3a^2-5a-4\) as a difference of two expressions when the first expression must be \(7a^2-2\).

Hints

- Represent the unknown second expression with a variable. - Use the relationship between a difference, its first expression, and its second expression. - Distribute the negative sign carefully before combining like terms.

Solution

1. Let the second expression be \(S\). Then \((7a^2-2)-S=3a^2-5a-4\). 2. Solve for \(S\): \(S=(7a^2-2)-(3a^2-5a-4)\). 3. Distribute the negative sign: \(S=7a^2-2-3a^2+5a+4\). 4. Combine like terms: \(S=4a^2+5a+2\). 5. Therefore, \(3a^2-5a-4=(7a^2-2)-(4a^2+5a+2)\).

Answer

\((7a^2-2)-(4a^2+5a+2)\)
5229909
The polynomial \(a^2b-3ab^2+4a-7\) is to be written as the sum of three expressions. Two expressions are given: Expression 1: \(2a^2b+5\) Expression 2: \(-ab^2-3a\) Find the third expression in simplest form.

Hints

- Add the two known expressions first. - Subtract their sum from the target polynomial. - Combine only terms with exactly the same variables and exponents.

Solution

1. Let the third expression be \(T\). Then \((2a^2b+5)+(-ab^2-3a)+T=a^2b-3ab^2+4a-7\). 2. Combine the known expressions: \(2a^2b-ab^2-3a+5+T=a^2b-3ab^2+4a-7\). 3. Subtract the known sum from the target polynomial: \(T=(a^2b-3ab^2+4a-7)-(2a^2b-ab^2-3a+5)\). 4. Distribute the negative sign: \(T=a^2b-3ab^2+4a-7-2a^2b+ab^2+3a-5\). 5. Combine like terms: \(T=-a^2b-2ab^2+7a-12\).

Answer

\(-a^2b-2ab^2+7a-12\)
5229939
Evaluate \(2a^2-[3ab-(a^2+2ab)]\) for \(a=5\) and \(b=-2\).

Hints

- Work from the innermost grouping symbols outward. - Pay close attention to the signs when removing parentheses. - Simplify the algebraic expression before substituting the values. - Substitute \(-2\) for \(b\), including its negative sign.

Solution

1. Simplify inside the brackets: \(3ab-(a^2+2ab)=3ab-a^2-2ab=ab-a^2\). 2. Simplify the full expression: \(2a^2-(ab-a^2)=2a^2-ab+a^2=3a^2-ab\). 3. Substitute \(a=5\) and \(b=-2\): \(3\cdot5^2-5\cdot(-2)=75+10=85\).

Answer

\(85\)
5229969
Let \(U=3m^2-5n\) and \(V=m^2+2n\). Simplify \(W=2[U-(V-U)]-3U\) as far as possible before substituting for \(U\) and \(V\). Then write \(W\) in terms of \(m\) and \(n\).

Hints

- First simplify using the symbols \(U\) and \(V\). - Track the signs carefully when removing parentheses. - After substituting, group the \(m^2\) terms and the \(n\) terms separately.

Solution

1. Simplify \(W\) using \(U\) and \(V\): \(2[U-V+U]-3U=2[2U-V]-3U\). 2. Distribute and combine like terms: \(4U-2V-3U=U-2V\). 3. Substitute the given expressions: \((3m^2-5n)-2(m^2+2n)\). 4. Distribute and combine like terms: \(3m^2-5n-2m^2-4n=m^2-9n\).

Answer

\(m^2-9n\)
5229979
Simplify \(2a^2b-[3ab^2-(4a^2b-2ab^2)+5a^2b]\), and then evaluate it for \(a=-2\) and \(b=3\).

Hints

- Work from the innermost grouping symbols outward. - Reverse every sign when subtracting a grouped expression. - Simplify the algebraic expression before substituting the values. - Remember that the square of a negative number is positive.

Solution

1. Remove the inner parentheses: \(2a^2b-[3ab^2-4a^2b+2ab^2+5a^2b]\). 2. Combine like terms inside the brackets: \(2a^2b-[5ab^2+a^2b]\). 3. Remove the brackets and combine like terms: \(2a^2b-5ab^2-a^2b=a^2b-5ab^2\). 4. Substitute \(a=-2\) and \(b=3\): \((-2)^2\cdot3-5\cdot(-2)\cdot3^2\). 5. Evaluate: \(4\cdot3-5\cdot(-2)\cdot9=12+90=102\).

Answer

\(102\)
5229989
Simplify \(4xy-\{2x^2-[3xy-(x^2-2xy)+4x^2]-5xy\}\), and then evaluate it for \(x=-1\) and \(y=-4\).

Hints

- Work from the innermost grouping symbols outward. - Group like terms, such as all \(x^2\) terms, before combining them. - The product of two negative numbers is positive. - Check every sign after removing a grouped expression.

Solution

1. Remove the innermost parentheses: \(4xy-\{2x^2-[3xy-x^2+2xy+4x^2]-5xy\}\). 2. Combine like terms inside the brackets: \(4xy-\{2x^2-[5xy+3x^2]-5xy\}\). 3. Remove the brackets: \(4xy-\{2x^2-5xy-3x^2-5xy\}\). 4. Combine like terms inside the braces: \(4xy-\{-x^2-10xy\}\). 5. Remove the braces and combine like terms: \(4xy+x^2+10xy=x^2+14xy\). 6. Substitute \(x=-1\) and \(y=-4\): \((-1)^2+14\cdot(-1)\cdot(-4)=1+56=57\).

Answer

\(57\)
5230019
Simplify \(x^2y-\{2xy^2-[3x^2y-(xy^2+x^2y)]\}\), and then evaluate it for \(x=-1\) and \(y=\frac{2}{3}\).

Hints

- Work from the innermost grouping symbols outward. - Reverse every sign when subtracting a grouped expression. - Simplify completely before substituting the values. - Evaluate exponents before multiplication.

Solution

1. Remove the innermost parentheses: \(x^2y-\{2xy^2-[3x^2y-xy^2-x^2y]\}\). 2. Combine like terms inside the brackets: \(x^2y-\{2xy^2-[2x^2y-xy^2]\}\). 3. Remove the brackets: \(x^2y-\{2xy^2-2x^2y+xy^2\}\). 4. Combine like terms inside the braces: \(x^2y-\{3xy^2-2x^2y\}\). 5. Remove the braces and combine like terms: \(x^2y-3xy^2+2x^2y=3x^2y-3xy^2\). 6. Substitute \(x=-1\) and \(y=\frac{2}{3}\): \(3\cdot(-1)^2\cdot\frac{2}{3}-3\cdot(-1)\cdot\left(\frac{2}{3}\right)^2\). 7. Evaluate: \(2+\frac{4}{3}=\frac{10}{3}\).

Answer

\(\frac{10}{3}\), or \(3\frac{1}{3}\)
5230589
Expand and simplify. a) \(\frac{2}{3}z(6z^2 - 9z + 12)\) b) \(-1.5m(2m^2 - 4m + 6)\) c) \((10x^3 - 5x^2 + 25x)\left(-\frac{1}{5}x\right)\)

Hints

- Determine the sign of each product before simplifying it. - Fractions and decimals follow the same multiplication rules as integers. - When multiplying powers with the same base, add the exponents. A variable with no written exponent has exponent \(1\).

Solution

1. For a), \(\frac{2}{3}z(6z^2 - 9z + 12) = 4z^3 - 6z^2 + 8z\). 2. For b), \(-1.5m(2m^2 - 4m + 6) = -3m^3 + 6m^2 - 9m\). 3. For c), \((10x^3 - 5x^2 + 25x)\left(-\frac{1}{5}x\right) = -2x^4 + x^3 - 5x^2\).

Answer

a) \(4z^3 - 6z^2 + 8z\) b) \(-3m^3 + 6m^2 - 9m\) c) \(-2x^4 + x^3 - 5x^2\)
5230619
Use the distributive property to expand. 1) \(6(3a - 4b + 7)\) 2) \((x^2 - 2x - 5)(-3)\) 3) \(0.4(10m - 5n + 15)\) 4) \((9r + 6s - 3)\left(-\frac{2}{3}\right)\)

Hints

- Multiply the outside factor by every term inside the parentheses. - Check the sign of each product, especially when two negative factors are multiplied. - Fractions and decimals distribute in the same way as integers.

Solution

1. \(6(3a - 4b + 7) = 18a - 24b + 42\). 2. \((x^2 - 2x - 5)(-3) = -3x^2 + 6x + 15\). 3. \(0.4(10m - 5n + 15) = 4m - 2n + 6\). 4. \((9r + 6s - 3)\left(-\frac{2}{3}\right) = -6r - 4s + 2\).

Answer

1) \(18a - 24b + 42\) 2) \(-3x^2 + 6x + 15\) 3) \(4m - 2n + 6\) 4) \(-6r - 4s + 2\)
5230649
Lucas and Sarah expand \(-3x^2(2x - 4y + 1)\). Lucas gets \(-6x^3 + 12x^2y - 1\). Sarah gets \(-6x^3 + 12x^2y - 3x^2\). Determine who is correct, and briefly describe the other student's error.

Hints

- Expand the expression yourself before comparing the answers. - Was every term inside the parentheses multiplied by the outside monomial? - What is the product of a quantity and \(1\)?

Solution

1. Distribute \(-3x^2\) to every term: \(-3x^2(2x - 4y + 1) = -6x^3 + 12x^2y - 3x^2\). 2. Sarah is correct. 3. Lucas changed \(+1\) to \(-1\) instead of multiplying it by \(-3x^2\).

Answer

Sarah is correct. Lucas failed to multiply the final term \(1\) by \(-3x^2\).
5230699
Expand and simplify. \(5x(x - 2y) - 3y(4x - y) + 22xy\)

Hints

- Expand one product at a time. - Pay close attention to the negative factor before the second product. - Combine terms only when they have the same variable factors. - Check that every product was expanded completely.

Solution

1. Expand the products: \(5x^2 - 10xy - 12xy + 3y^2 + 22xy\). 2. Combine the \(xy\)-terms: \((-10 - 12 + 22)xy = 0\). 3. The simplified expression is \(5x^2 + 3y^2\).

Answer

\(5x^2 + 3y^2\)
5230709
Expand and simplify. \(0.5k(4k - 6m) - 2m(k - 3m) - 2k^2\)

Hints

- Distribute the negative factor carefully. - Remember that \(km\) and \(mk\) are the same product. - Look for terms that cancel. - Multiply the decimal coefficient just as you would any other number.

Solution

1. Expand the first product: \(0.5k(4k - 6m) = 2k^2 - 3km\). 2. Expand the second product: \(-2m(k - 3m) = -2km + 6m^2\). 3. Combine all terms: \(2k^2 - 3km - 2km + 6m^2 - 2k^2 = 6m^2 - 5km\).

Answer

\(6m^2 - 5km\)
5230729
Find the product. \(5xy\left(\frac{2}{5}x^2y - 10xy^2 + \frac{1}{2}y\right)\)

Hints

- Multiply every term in the polynomial by the monomial outside. - Multiply the coefficients first, then handle each variable. - When multiplying \(x^2\) by \(x\), add the exponents. - Choose either fraction or decimal form for the coefficient calculation and use it consistently.

Solution

1. Multiply the first term: \(5xy\left(\frac{2}{5}x^2y\right) = 2x^3y^2\). 2. Multiply the second term: \(5xy(-10xy^2) = -50x^2y^3\). 3. Multiply the third term: \(5xy\left(\frac{1}{2}y\right) = \frac{5}{2}xy^2\). 4. The product is \(2x^3y^2 - 50x^2y^3 + \frac{5}{2}xy^2\).

Answer

\(2x^3y^2 - 50x^2y^3 + \frac{5}{2}xy^2\)
5230759
Expand and simplify. \(4x(3x - 2y) - 2x(y + 5x) + 7xy\)

Hints

- Pay close attention to the sign of each outside factor. - Group terms by their variable factors before combining. - Terms can be combined only when their variables and exponents match exactly.

Solution

1. Expand both products: \(12x^2 - 8xy - 2xy - 10x^2 + 7xy\). 2. Combine the \(x^2\)-terms: \(12x^2 - 10x^2 = 2x^2\). 3. Combine the \(xy\)-terms: \(-8xy - 2xy + 7xy = -3xy\). 4. The result is \(2x^2 - 3xy\).

Answer

\(2x^2 - 3xy\)
5230769
Expand and simplify. \(2a(4b - 3a) - 5(a^2 - 2ab) - a(3a + b)\)

Hints

- Distribute negative factors carefully. - Expand each product separately before combining terms. - Group terms with the same variable factors.

Solution

1. Expand each product: \(8ab - 6a^2 - 5a^2 + 10ab - 3a^2 - ab\). 2. Combine the \(a^2\)-terms: \(-6a^2 - 5a^2 - 3a^2 = -14a^2\). 3. Combine the \(ab\)-terms: \(8ab + 10ab - ab = 17ab\). 4. The result is \(-14a^2 + 17ab\).

Answer

\(-14a^2 + 17ab\)
5230809
Expand and simplify. \(1.2a(2a - 0.5b) - 0.4(3a^2 - 5ab + 2b^2) + 0.5b(4a - 6b)\)

Hints

- Multiply every term inside each set of parentheses by its outside factor. - Check the sign of each product. - Group the \(a^2\)-terms, \(ab\)-terms, and \(b^2\)-terms separately. - Remember that \(ab = ba\).

Solution

1. Expand the first product: \(1.2a(2a - 0.5b) = 2.4a^2 - 0.6ab\). 2. Expand the second product: \(-0.4(3a^2 - 5ab + 2b^2) = -1.2a^2 + 2ab - 0.8b^2\). 3. Expand the third product: \(0.5b(4a - 6b) = 2ab - 3b^2\). 4. Combine like terms: \(1.2a^2 + 3.4ab - 3.8b^2\).

Answer

\(1.2a^2 + 3.4ab - 3.8b^2\)
5230859
Expand and simplify. \(1.5(4x^2 - 2x + 6) - 1.2(5x^2 - 10x - 5)\)

Hints

- Distribute each decimal coefficient to every term. - Pay close attention to the minus sign before the second product. - Do not combine \(x^2\)-terms with \(x\)-terms. - Remove all parentheses before grouping like terms.

Solution

1. Expand the first product: \(1.5(4x^2 - 2x + 6) = 6x^2 - 3x + 9\). 2. Expand the second product and subtract it: \(-1.2(5x^2 - 10x - 5) = -6x^2 + 12x + 6\). 3. Combine like terms: \(6x^2 - 3x + 9 - 6x^2 + 12x + 6 = 9x + 15\).

Answer

\(9x + 15\)
5230879
A rectangle is three times as long as it is wide. When its length is shortened by \(2\,\text{in.}\), its area decreases by \(12\,\text{in.}^2\). a) Find the original width and length. b) Explain why the decrease in area depends directly on the rectangle's width.

Hints

- Express the length in terms of the width. - Write the area before and after the change. - Set the difference between the areas equal to \(12\). - Visualize the rectangular strip that is removed.

Solution

1. Let \(w\) inches be the width. The length is \(3w\) inches, so the original area is \(3w^2\). 2. After the length is shortened, the new area is \((3w - 2)w = 3w^2 - 2w\). 3. The area decreases by \(12\,\text{in.}^2\), so \(3w^2 - (3w^2 - 2w) = 12\). 4. Simplify: \(2w = 12\), so \(w = 6\). 5. The original length is \(3 \cdot 6\,\text{in.} = 18\,\text{in.}\). 6. The removed region is a strip \(2\,\text{in.}\) long and \(w\) inches wide, so its area is \(2w\).

Answer

a) The original width is \(6\,\text{in.}\), and the original length is \(18\,\text{in.}\). b) Shortening only the length removes a \(2\,\text{in.}\)-by-\(w\) strip, so the area decrease is \(2w\).
5230889
Two gardeners each start with a square garden bed of side length \(a\) feet. Gardener A extends one side by \(2\,\text{ft}\), while Gardener B extends one side by \(5\,\text{ft}\). Gardener B''s new bed has \(15\,\text{ft}^2\) more area than Gardener A''s new bed. Find the original side length \(a\).

Hints

- Write an area expression for each extended bed. - Subtract the smaller new area from the larger new area. - Look for terms that cancel. - Set the remaining difference equal to \(15\).

Solution

1. Gardener A's new area is \(a(a + 2) = a^2 + 2a\). 2. Gardener B's new area is \(a(a + 5) = a^2 + 5a\). 3. The difference in area is \((a^2 + 5a) - (a^2 + 2a) = 3a\). 4. Set the difference equal to \(15\): \(3a = 15\). 5. Divide by \(3\): \(a = 5\).

Answer

The original side length of each square garden bed is \(5\,\text{ft}\).
5230949
Expand and simplify. 1) \((4a + b)(a - 3b)\) 2) \((2x - 3y)(5x - 2y)\) 3) \((m + n)(m - n)\) 4) \((x + 2)(x + 3) - x(x + 5)\)

Hints

- Remember that \(ab = ba\) when identifying like terms. - In part 4, expand both products before subtracting. - Look for terms that cancel in part 3.

Solution

1. \((4a + b)(a - 3b) = 4a^2 - 12ab + ab - 3b^2 = 4a^2 - 11ab - 3b^2\). 2. \((2x - 3y)(5x - 2y) = 10x^2 - 4xy - 15xy + 6y^2 = 10x^2 - 19xy + 6y^2\). 3. \((m + n)(m - n) = m^2 - mn + mn - n^2 = m^2 - n^2\). 4. \((x + 2)(x + 3) - x(x + 5) = x^2 + 5x + 6 - x^2 - 5x = 6\).

Answer

1) \(4a^2 - 11ab - 3b^2\) 2) \(10x^2 - 19xy + 6y^2\) 3) \(m^2 - n^2\) 4) \(6\)
5230959
Expand and simplify. a) \((y + 4)(y^2 - 4y + 16)\) b) \((z - 2)(z^2 + 2z + 4)\)

Hints

- Multiply every term in the first factor by every term in the second. - Check the signs of all partial products. - After expanding, look for pairs of terms that cancel.

Solution

1. For a), \((y + 4)(y^2 - 4y + 16) = y^3 - 4y^2 + 16y + 4y^2 - 16y + 64 = y^3 + 64\). 2. For b), \((z - 2)(z^2 + 2z + 4) = z^3 + 2z^2 + 4z - 2z^2 - 4z - 8 = z^3 - 8\).

Answer

a) \(y^3 + 64\) b) \(z^3 - 8\)
5230969
Expand the product, then simplify the entire expression. \((2x + 1)(4x^2 - 2x + 1) - 8x^3\)

Hints

- Expand the product completely before considering the final subtraction. - Remember that \(x \cdot x^2 = x^3\). - Look for terms with equal magnitude and opposite signs.

Solution

1. Expand the product: \((2x + 1)(4x^2 - 2x + 1) = 8x^3 - 4x^2 + 2x + 4x^2 - 2x + 1\). 2. Combine terms in the product: \(8x^3 + 1\). 3. Subtract \(8x^3\): \(8x^3 + 1 - 8x^3 = 1\).

Answer

\(1\)
5230989
Expand each product and write the result in descending powers of the variable. 1) \((2x + 1)(x - 4)\) 2) \((3a - b)(2a + b)\) 3) \((5 - k)(k + 2)\)

Hints

- Multiplying a variable by itself produces a square. - Recognize \(ab\) and \(ba\) as like terms. - In descending order, write the highest exponent first. - Recheck every sign.

Solution

1. \((2x + 1)(x - 4) = 2x^2 - 8x + x - 4 = 2x^2 - 7x - 4\). 2. \((3a - b)(2a + b) = 6a^2 + 3ab - 2ab - b^2 = 6a^2 + ab - b^2\). 3. \((5 - k)(k + 2) = 5k + 10 - k^2 - 2k = -k^2 + 3k + 10\).

Answer

1) \(2x^2 - 7x - 4\) 2) \(6a^2 + ab - b^2\) 3) \(-k^2 + 3k + 10\)
5231009
Expand and combine like terms. 1) \((2x^2 - 3y^2)(4x^2 + y^2)\) 2) \((3a^2b + 2a)(5ab^2 - 4b)\) 3) \((-x^2y - 2)(3x^2y + 5)\)

Hints

- Add exponents when multiplying powers with the same base. - Track every negative sign through each partial product. - Like terms must match in every variable and exponent.

Solution

1. \((2x^2 - 3y^2)(4x^2 + y^2) = 8x^4 + 2x^2y^2 - 12x^2y^2 - 3y^4 = 8x^4 - 10x^2y^2 - 3y^4\). 2. \((3a^2b + 2a)(5ab^2 - 4b) = 15a^3b^3 - 12a^2b^2 + 10a^2b^2 - 8ab = 15a^3b^3 - 2a^2b^2 - 8ab\). 3. \((-x^2y - 2)(3x^2y + 5) = -3x^4y^2 - 5x^2y - 6x^2y - 10 = -3x^4y^2 - 11x^2y - 10\).

Answer

1) \(8x^4 - 10x^2y^2 - 3y^4\) 2) \(15a^3b^3 - 2a^2b^2 - 8ab\) 3) \(-3x^4y^2 - 11x^2y - 10\)
5231029
Expand and simplify. \((a - 2b)(a^2 + 2ab + 4b^2 - 1)\)

Hints

- Multiply the first term of the left factor by the entire second factor, then do the same with the second term. - Use the power rules, such as \(a \cdot a^2 = a^3\). - Pay close attention when multiplying by \(-2b\). - Group matching variable terms to find cancellations.

Solution

1. Multiply \(a\) by every term: \(a^3 + 2a^2b + 4ab^2 - a\). 2. Multiply \(-2b\) by every term: \(-2a^2b - 4ab^2 - 8b^3 + 2b\). 3. Combine like terms. The \(a^2b\)-terms and \(ab^2\)-terms cancel, leaving \(a^3 - 8b^3 - a + 2b\).

Answer

\(a^3 - 8b^3 - a + 2b\)
5231039
Expand and simplify. \((x^2 - 4xy + 3y^2)(x + 2y)\)

Hints

- There should be six partial products before combining terms. - Check each sign carefully. - Combine only terms with exactly the same variables and exponents. - Mark each term after using it to avoid omissions.

Solution

1. Form all six partial products: \(x^3 + 2x^2y - 4x^2y - 8xy^2 + 3xy^2 + 6y^3\). 2. Combine like terms: \(x^3 + (2 - 4)x^2y + (-8 + 3)xy^2 + 6y^3\). 3. The result is \(x^3 - 2x^2y - 5xy^2 + 6y^3\).

Answer

\(x^3 - 2x^2y - 5xy^2 + 6y^3\)
5231049
Expand and simplify. \((2a - 3b)(3a^2 + ab - 2b^2)\)

Hints

- Remember that a negative times a negative is positive. - Arrange like terms next to each other before combining. - Check that every term in one factor was multiplied by every term in the other.

Solution

1. Form all partial products: \(6a^3 + 2a^2b - 4ab^2 - 9a^2b - 3ab^2 + 6b^3\). 2. Combine like terms: \(6a^3 + (2 - 9)a^2b + (-4 - 3)ab^2 + 6b^3\). 3. The result is \(6a^3 - 7a^2b - 7ab^2 + 6b^3\).

Answer

\(6a^3 - 7a^2b - 7ab^2 + 6b^3\)
5231059
Expand and simplify. \((4x - 3)(2x^2 + x - 5)\)

Hints

- Use the distributive property to multiply every term in one factor by every term in the other. - Apply the sign rules carefully. - Combine terms only when they have the same power of \(x\). - Organizing the partial products in rows may help.

Solution

1. Form the partial products: \(8x^3 + 4x^2 - 20x - 6x^2 - 3x + 15\). 2. Combine terms with the same power of \(x\): \(8x^3 - 2x^2 - 23x + 15\).

Answer

\(8x^3 - 2x^2 - 23x + 15\)
5231069
Find the product and simplify. \((2a^3 - 3a^2b + ab^2 - b^3)(a + 2b)\)

Hints

- Add exponents when multiplying powers with the same base. - Multiply every term in the first polynomial by both terms in the second. - Do not combine terms such as \(a^3b\) and \(a^2b^2\). - Verify that you formed all eight partial products.

Solution

1. Form all eight partial products: \(2a^4 + 4a^3b - 3a^3b - 6a^2b^2 + a^2b^2 + 2ab^3 - ab^3 - 2b^4\). 2. Combine like terms: \(2a^4 + a^3b - 5a^2b^2 + ab^3 - 2b^4\).

Answer

\(2a^4 + a^3b - 5a^2b^2 + ab^3 - 2b^4\)
5231079
Expand and simplify. \((2y^3 - y^2 + 4y - 1)(y^2 - 3)\)

Hints

- A four-term polynomial times a two-term polynomial creates eight partial products. - Pay close attention when multiplying by \(-3\). - Add exponents when multiplying powers of \(y\). - Sort the partial products by exponent before combining.

Solution

1. Form the eight partial products: \(2y^5 - 6y^3 - y^4 + 3y^2 + 4y^3 - 12y - y^2 + 3\). 2. Arrange by descending powers and combine like terms: \(2y^5 - y^4 - 2y^3 + 2y^2 - 12y + 3\).

Answer

\(2y^5 - y^4 - 2y^3 + 2y^2 - 12y + 3\)
5231089
Expand and simplify. \((x^2 - 2x + 1)(x^3 + 3x^2 - 5x + 2)\)

Hints

- Multiply each term in the first polynomial by the entire second polynomial. - Arrange partial products by powers of \(x\) before combining. - Remember that \(x^2 \cdot x^3 = x^5\). - Track the signs carefully, especially in the products involving \(-2x\).

Solution

1. Multiply each term in the first factor by the second polynomial: \(x^2(x^3 + 3x^2 - 5x + 2) = x^5 + 3x^4 - 5x^3 + 2x^2\), \(-2x(x^3 + 3x^2 - 5x + 2) = -2x^4 - 6x^3 + 10x^2 - 4x\), and \(x^3 + 3x^2 - 5x + 2\). 2. Combine equal powers: \(x^5 + x^4 - 10x^3 + 15x^2 - 9x + 2\).

Answer

\(x^5 + x^4 - 10x^3 + 15x^2 - 9x + 2\)
5231139
Expand and simplify. \(\left(\frac{2}{3}a - \frac{1}{2}b\right)\left(\frac{3}{4}a + \frac{1}{3}b - 2\right)\)

Hints

- Multiply every term in the first factor by every term in the second. - Track the signs carefully. - Use a common denominator to combine fractional coefficients. - Combine only terms with matching variable factors.

Solution

1. Form the six partial products: \(\frac{1}{2}a^2 + \frac{2}{9}ab - \frac{4}{3}a - \frac{3}{8}ab - \frac{1}{6}b^2 + b\). 2. Combine the \(ab\)-terms: \(\frac{2}{9}ab - \frac{3}{8}ab = \left(\frac{16}{72} - \frac{27}{72}\right)ab = -\frac{11}{72}ab\). 3. The result is \(\frac{1}{2}a^2 - \frac{11}{72}ab - \frac{4}{3}a - \frac{1}{6}b^2 + b\).

Answer

\(\frac{1}{2}a^2 - \frac{11}{72}ab - \frac{4}{3}a - \frac{1}{6}b^2 + b\)
5231159
Simplify the expression, then evaluate it for \(x = 0.75\). \((2x - 3)(x + 4) - (x - 2)(2x + 1)\)

Hints

- Simplifying first is more efficient than substituting immediately. - A minus sign before parentheses changes every sign inside. - Expand each product systematically. - Combine terms with the same power of \(x\).

Solution

1. Expand both products: \((2x^2 + 5x - 12) - (2x^2 - 3x - 2)\). 2. Remove the second parentheses and combine like terms: \(2x^2 + 5x - 12 - 2x^2 + 3x + 2 = 8x - 10\). 3. Substitute \(x = 0.75\): \(8 \cdot 0.75 - 10 = 6 - 10 = -4\).

Answer

Simplified expression: \(8x - 10\) Value at \(x = 0.75\): \(-4\)
5231189
Expand and simplify. 1) \((a + 6)(3a - 2)\) 2) \(4z + 2 \cdot 3(2z - 5)\)

Hints

- In a product of two binomials, multiply every term in one factor by every term in the other. - In a chain of multiplication, factors may be regrouped and reordered. - Combine only terms with matching variables and exponents. - Track all signs carefully.

Solution

1. \((a + 6)(3a - 2) = 3a^2 - 2a + 18a - 12 = 3a^2 + 16a - 12\). 2. Use the associative property: \(2 \cdot 3(2z - 5) = 6(2z - 5) = 12z - 30\). Then \(4z + 12z - 30 = 16z - 30\).

Answer

1) \(3a^2 + 16a - 12\) 2) \(16z - 30\)
5231279
Before multiplying, arrange the terms in each factor in descending powers of \(x\). Then expand and simplify. \((5 + 3x^2 - 4x)(2x - 3 + x^2)\)

Hints

- First arrange each polynomial in descending powers. - Track the signs of all partial products. - Multiply every term in one factor by every term in the other. - Combine terms with the same power of \(x\).

Solution

1. Rewrite the factors as \((3x^2 - 4x + 5)(x^2 + 2x - 3)\). 2. Form the partial products: \(3x^4 + 6x^3 - 9x^2 - 4x^3 - 8x^2 + 12x + 5x^2 + 10x - 15\). 3. Combine like powers: \(3x^4 + 2x^3 - 12x^2 + 22x - 15\).

Answer

\(3x^4 + 2x^3 - 12x^2 + 22x - 15\)
5231289
Before multiplying, arrange the first factor in descending powers of \(a\). Then expand and simplify. \((2b^2 - 3ab + a^2)(4a - 5b)\)

Hints

- Arrange the first polynomial by powers of \(a\). - Terms such as \(a^2b\) and \(ab^2\) are not like terms. - Track negative signs carefully. - Combine only terms with exactly matching variable factors.

Solution

1. Rewrite the first factor as \(a^2 - 3ab + 2b^2\). 2. Form the partial products: \(4a^3 - 5a^2b - 12a^2b + 15ab^2 + 8ab^2 - 10b^3\). 3. Combine like terms: \(4a^3 - 17a^2b + 23ab^2 - 10b^3\).

Answer

\(4a^3 - 17a^2b + 23ab^2 - 10b^3\)
5231299
Expand and simplify. 1) \((2a^2 - 3ab + b^2)(4a - 5b)\) 2) \((x^2 - 3x + 2)(2x^2 + x - 4)\)

Hints

- Multiply every term in one factor by every term in the other. - Apply the sign rules carefully. - Arrange the result by powers before combining. - Add exponents when multiplying powers with the same base.

Solution

1. Form the partial products and combine like terms: \(8a^3 - 10a^2b - 12a^2b + 15ab^2 + 4ab^2 - 5b^3 = 8a^3 - 22a^2b + 19ab^2 - 5b^3\). 2. Expand and combine equal powers: \(2x^4 + x^3 - 4x^2 - 6x^3 - 3x^2 + 12x + 4x^2 + 2x - 8 = 2x^4 - 5x^3 - 3x^2 + 14x - 8\).

Answer

1) \(8a^3 - 22a^2b + 19ab^2 - 5b^3\) 2) \(2x^4 - 5x^3 - 3x^2 + 14x - 8\)
5231309
Let \(T = (3x^2 - 2x + 1)(2x - 5)\). a) Expand and simplify \(T\). b) What is the coefficient of the \(x^2\)-term in the result? c) Evaluate \(T\) for \(x = 2\).

Hints

- A coefficient is the numerical factor of a variable term. - For part c), you may substitute into either the original product or the expanded expression. - Include the sign when combining the \(x^2\)-terms.

Solution

1. Expand: \(6x^3 - 15x^2 - 4x^2 + 10x + 2x - 5\). 2. Combine like terms: \(T = 6x^3 - 19x^2 + 12x - 5\). 3. The coefficient of \(x^2\) is \(-19\). 4. For \(x = 2\), \(T = 6 \cdot 2^3 - 19 \cdot 2^2 + 12 \cdot 2 - 5 = -9\).

Answer

a) \(6x^3 - 19x^2 + 12x - 5\) b) \(-19\) c) \(-9\)
5231329
Let \(u = m + 2n\) and \(v = m - n\). Rewrite each expression using only \(m\) and \(n\), then simplify. 1) \(3u + 4v\) 2) \(2u - v\) 3) \(um - vm\) 4) \(uv\)

Hints

- A minus sign before parentheses changes every sign inside. - In part 3, factoring out \(m\) may simplify the setup. - When multiplying two binomials, multiply every term in one by every term in the other.

Solution

1. \(3(m + 2n) + 4(m - n) = 7m + 2n\). 2. \(2(m + 2n) - (m - n) = m + 5n\). 3. \(m(m + 2n) - m(m - n) = m^2 + 2mn - m^2 + mn = 3mn\). 4. \((m + 2n)(m - n) = m^2 - mn + 2mn - 2n^2 = m^2 + mn - 2n^2\).

Answer

1) \(7m + 2n\) 2) \(m + 5n\) 3) \(3mn\) 4) \(m^2 + mn - 2n^2\)
5231339
Let \(T(a) = (a - 5)(a + 5) + (a - 1)(a + 1)\). Simplify first, then evaluate at \(a = 0.4\).

Hints

- Simplify the conjugate products before substituting. - Combine like terms. - Use parentheses when squaring the decimal input.

Solution

1. Use the difference of squares: \((a - 5)(a + 5) = a^2 - 25\) and \((a - 1)(a + 1) = a^2 - 1\). 2. Thus, \(T(a) = 2a^2 - 26\). 3. Substitute \(a = 0.4\): \(2 \cdot (0.4)^2 - 26 = 2 \cdot 0.16 - 26 = -25.68\).

Answer

\(-25.68\)
5231619
A rectangle is \(7\,\text{in.}\) longer than it is wide. If the length is decreased by \(2\,\text{in.}\) and the width is increased by \(5\,\text{in.}\), the new figure is a square. The square''s area is \(55\,\text{in.}^2\) greater than the rectangle''s original area. Find the side length of the square.

Hints

- Express the original dimensions using one variable. - Determine the common side length after the changes. - Write and compare the two area expressions. - Expand the square and simplify the equation.

Solution

1. Let \(x\) inches be the original width. The original length is \(x + 7\), so the original area is \(x(x + 7) = x^2 + 7x\). 2. After the changes, both dimensions are \(x + 5\), so the square's area is \((x + 5)^2 = x^2 + 10x + 25\). 3. The square's area is \(55\,\text{in.}^2\) greater: \(x^2 + 10x + 25 = x^2 + 7x + 55\). 4. Subtract \(x^2 + 7x\): \(3x + 25 = 55\). 5. Subtract \(25\): \(3x = 30\), so \(x = 10\). 6. The square's side length is \(x + 5 = 15\,\text{in.}\).

Answer

The square''s side length is \(15\,\text{in.}\).
5231629
A rectangle is \(8\,\text{in.}\) longer than it is wide. If the length is shortened by \(3\,\text{in.}\) and the width is increased by \(2\,\text{in.}\), the new rectangle has the same area as the original rectangle. Find the original rectangle''s perimeter.

Hints

- Express the original length in terms of the width. - Write the new dimensions after both changes. - Set the original and new area expressions equal. - Use the original dimensions to calculate the requested perimeter.

Solution

1. Let \(b\) inches be the original width. The original length is \(b + 8\), so the original area is \(b(b + 8) = b^2 + 8b\). 2. The new dimensions are \(b + 2\) and \(b + 5\), so the new area is \((b + 2)(b + 5) = b^2 + 7b + 10\). 3. Set the areas equal: \(b^2 + 8b = b^2 + 7b + 10\). 4. Subtract \(b^2 + 7b\): \(b = 10\). 5. The original dimensions are \(10\,\text{in.}\) and \(18\,\text{in.}\). 6. The perimeter is \(2(10 + 18) = 56\,\text{in.}\).

Answer

The original rectangle''s perimeter is \(56\,\text{in.}\).
5231699
A rectangle is three times as long as it is wide. If the width is increased by \(2\,\text{in.}\) and the length is decreased by \(3\,\text{in.}\), the area increases by \(15\,\text{in.}^2\). Find the original dimensions.

Hints

- Express the original length in terms of the width. - Write area expressions before and after the changes. - Relate the two areas using the stated increase. - Expand the product and look for quadratic terms that cancel.

Solution

1. Let \(w\) inches be the original width. The original length is \(3w\), so the original area is \(3w^2\). 2. The new dimensions are \(w + 2\) and \(3w - 3\), so the new area is \((w + 2)(3w - 3)\). 3. The area increases by \(15\,\text{in.}^2\), so \((w + 2)(3w - 3) = 3w^2 + 15\). 4. Expand: \(3w^2 + 3w - 6 = 3w^2 + 15\). 5. Subtract \(3w^2\) and add \(6\): \(3w = 21\), so \(w = 7\). 6. The original length is \(3 \cdot 7\,\text{in.} = 21\,\text{in.}\).

Answer

The original rectangle was \(7\,\text{in.}\) wide and \(21\,\text{in.}\) long.
5231739
Expand and simplify. \(4a(2a - 3b) - (a - b)(3a + 2b) - 5a^2\)

Hints

- Pay close attention to the minus sign before the binomial product. - Expand the product completely before applying the outside subtraction. - Group terms with the same variable factors.

Solution

1. Expand the first product: \(4a(2a - 3b) = 8a^2 - 12ab\). 2. Expand the binomial product: \((a - b)(3a + 2b) = 3a^2 - ab - 2b^2\). 3. Subtract this product and combine like terms: \(8a^2 - 12ab - 3a^2 + ab + 2b^2 - 5a^2 = 2b^2 - 11ab\).

Answer

\(2b^2 - 11ab\)
5231779
A rectangular garden bed is \(5\,\text{ft}\) longer than it is wide. If its width is increased by \(2\,\text{ft}\) and its length is increased by \(3\,\text{ft}\), its area increases by \(41\,\text{ft}^2\). Find the original dimensions.

Hints

- Express the original length in terms of the width. - Write the original and new area expressions. - Set the new area equal to the original area plus \(41\). - Expand carefully and simplify.

Solution

1. Let \(x\) feet be the original width. The original length is \(x + 5\), so the original area is \(x(x + 5) = x^2 + 5x\). 2. The new dimensions are \(x + 2\) and \(x + 8\), so the new area is \((x + 2)(x + 8) = x^2 + 10x + 16\). 3. The area increases by \(41\,\text{ft}^2\), so \(x^2 + 10x + 16 = x^2 + 5x + 41\). 4. Subtract \(x^2 + 5x\): \(5x + 16 = 41\). 5. Subtract \(16\): \(5x = 25\), so \(x = 5\). 6. The original length is \(5\,\text{ft} + 5\,\text{ft} = 10\,\text{ft}\).

Answer

The garden bed was originally \(5\,\text{ft}\) wide and \(10\,\text{ft}\) long.
5232069
Expand and simplify. \((2x^2+0.5y)^2-(2x^2-0.5y)^2\)

Hints

- Expand each binomial square separately. - Distribute the subtraction sign across every term in the second polynomial. - Look for terms that cancel.

Solution

1. Expand the first square: \((2x^2+0.5y)^2=4x^4+2x^2y+0.25y^2\). 2. Expand the second square: \((2x^2-0.5y)^2=4x^4-2x^2y+0.25y^2\). 3. Subtract the second polynomial: \(4x^4+2x^2y+0.25y^2-4x^4+2x^2y-0.25y^2\). 4. Combine like terms to get \(4x^2y\).

Answer

\(4x^2y\)
5232129
Expand and simplify each expression. a) \(4(y-1)^2+(y+2)(y-2)\) b) \((3a+2)^2-3(a^2-4)\)

Hints

- Expand each product before combining terms. - Recognize both a binomial square and a product of a sum and difference. - In part b), distribute the negative factor carefully.

Solution

1. a) Expand the binomial square and the product of a sum and difference: \(4(y^2-2y+1)+(y^2-4)\). 2. Distribute and combine like terms: \(4y^2-8y+4+y^2-4=5y^2-8y\). 3. b) Expand both parts: \((3a+2)^2=9a^2+12a+4\) and \(-3(a^2-4)=-3a^2+12\). 4. Combine like terms: \(9a^2+12a+4-3a^2+12=6a^2+12a+16\).

Answer

a) \(5y^2-8y\) b) \(6a^2+12a+16\)
5232239
Expand and simplify. \(\left((2r+3s)^2-(2r-3s)^2\right)\left(\frac{1}{2}rs\right)\)

Hints

- Expand the two binomial squares first. - Distribute the subtraction sign across the second polynomial. - Simplify the expression in parentheses before multiplying by the outside factor.

Solution

1. Expand the binomial squares: \((2r+3s)^2=4r^2+12rs+9s^2\) and \((2r-3s)^2=4r^2-12rs+9s^2\). 2. Subtract: \((4r^2+12rs+9s^2)-(4r^2-12rs+9s^2)=24rs\). 3. Multiply by the outside factor: \((24rs)\left(\frac{1}{2}rs\right)=12r^2s^2\).

Answer

\(12r^2s^2\)
5232399
Expand and simplify. \(2(a+5)^2-(a-4)^2\)

Hints

- Expand both binomial squares first. - Apply the outside factor to every term. - Distribute the subtraction sign across the second polynomial.

Solution

1. Expand the binomial squares: \((a+5)^2=a^2+10a+25\) and \((a-4)^2=a^2-8a+16\). 2. Substitute and distribute: \(2(a^2+10a+25)-(a^2-8a+16)\). 3. Remove parentheses: \(2a^2+20a+50-a^2+8a-16\). 4. Combine like terms to get \(a^2+28a+34\).

Answer

\(a^2+28a+34\)
5232409
Expand and simplify completely. \((3x-2y)^2+3(x+y)(x-y)-2x(x-4y)\)

Hints

- Expand each product separately. - Recognize the product \((x+y)(x-y)\). - Distribute \(-2x\) to both terms in the final factor. - Combine like terms only after all products are expanded.

Solution

1. Expand the first square: \((3x-2y)^2=9x^2-12xy+4y^2\). 2. Use the difference-of-squares identity: \(3(x+y)(x-y)=3x^2-3y^2\). 3. Distribute in the last term: \(-2x(x-4y)=-2x^2+8xy\). 4. Combine like terms: \((9+3-2)x^2+(-12+8)xy+(4-3)y^2=10x^2-4xy+y^2\).

Answer

\(10x^2-4xy+y^2\)
5232759
Expand and simplify. \((3x+2y)(3x-2y)-(3x-y)^2\)

Hints

- Identify the sum-and-difference product. - Expand the binomial square separately. - Distribute the subtraction sign before combining like terms.

Solution

1. Apply the difference-of-squares identity: \((3x+2y)(3x-2y)=9x^2-4y^2\). 2. Expand the binomial square: \((3x-y)^2=9x^2-6xy+y^2\). 3. Subtract and combine like terms: \(9x^2-4y^2-(9x^2-6xy+y^2)=6xy-5y^2\).

Answer

\(6xy-5y^2\)
5232769
Expand and simplify. \(\frac{1}{4}b\left((b^2+4)^2-(b^2-4)^2\right)\)

Hints

- Expand both squares inside the parentheses first. - Distribute the subtraction sign carefully. - Apply the product rule for exponents in the final multiplication.

Solution

1. Expand the squares: \((b^2+4)^2=b^4+8b^2+16\) and \((b^2-4)^2=b^4-8b^2+16\). 2. Subtract: \((b^4+8b^2+16)-(b^4-8b^2+16)=16b^2\). 3. Multiply by the outside factor: \(\frac{1}{4}b(16b^2)=4b^3\).

Answer

\(4b^3\)
5233069
Let \(B(a) = 2a(3a - 1) - (a + 2)(6a - 5)\). Simplify the expression completely, then evaluate it for \(a = -\frac{2}{3}\).

Hints

- Expand the two products separately. - Keep the second product in parentheses when subtracting it. - Combine the \(a^2\)-terms, \(a\)-terms, and constants separately. - Substitute only after simplifying completely.

Solution

1. Expand the first product: \(2a(3a - 1) = 6a^2 - 2a\). 2. Expand the second product: \((a + 2)(6a - 5) = 6a^2 + 7a - 10\). 3. Subtract and combine like terms: \(6a^2 - 2a - (6a^2 + 7a - 10) = -9a + 10\). 4. Evaluate: \(-9 \cdot \left(-\frac{2}{3}\right) + 10 = 16\).

Answer

\(16\)
5233079
For numbers close to \(1\), the approximation \((1 + a)(1 + b) \approx 1 + a + b\) can be useful when \(a\) and \(b\) are very small. a) Expand \((1 + a)(1 + b)\). Which term is omitted by the approximation? b) Use the approximation to estimate \(1.002 \cdot 1.006\). c) Find the exact product and the difference between the exact value and the estimate.

Hints

- Multiply every term in the first binomial by every term in the second. - Write each decimal as \(1\) plus a small amount. - The error is the difference between the exact product and the estimate.

Solution

1. Expand: \((1 + a)(1 + b) = 1 + a + b + ab\). The approximation omits \(ab\). 2. Here \(a = 0.002\) and \(b = 0.006\), so the estimate is \(1 + 0.002 + 0.006 = 1.008\). 3. The exact product is \(1.002 \cdot 1.006 = 1.008012\). 4. The difference is \(1.008012 - 1.008 = 0.000012\).

Answer

a) \((1 + a)(1 + b) = 1 + a + b + ab\); the omitted term is \(ab\) b) \(1.008\) c) Exact product: \(1.008012\); difference: \(0.000012\)
5233159
Simplify the expression. Then evaluate it for the given values: \(T(a, b) = 4a(a - 2b) + 2b(4a + b) - 3a^2\) Use \(a = 1.2\) and \(b = -0.5\).

Hints

- Distribute each factor across its parentheses. - Watch the signs as you combine like terms. - Look for terms that cancel. - Substitute the values after simplifying.

Solution

1. Distribute: \(4a(a - 2b) = 4a^2 - 8ab\) and \(2b(4a + b) = 8ab + 2b^2\). 2. Combine the expressions: \(4a^2 - 8ab + 8ab + 2b^2 - 3a^2\). 3. The opposite \(ab\)-terms cancel, so \(T(a,b) = a^2 + 2b^2\). 4. Substitute: \((1.2)^2 + 2 \cdot (-0.5)^2 = 1.44 + 2 \cdot 0.25 = 1.94\).

Answer

Simplified expression: \(a^2 + 2b^2\) Value: \(1.94\)
5233169
Consider the two expressions \(A = x(2x + y) - y(x - 3y)\) \(B = 2(x^2 + y^2) + y^2\). a) Use algebraic properties to show that \(A\) and \(B\) are equivalent. b) Find their common value when \(x = -5\) and \(y = \frac{1}{3}\).

Hints

- Simplify each expression separately and compare the results. - Remember that \(xy = yx\). - A minus sign before parentheses changes the sign of each term when the parentheses are removed. - Substitute into the simpler equivalent expression.

Solution

1. Simplify \(A\): \(A = 2x^2 + xy - xy + 3y^2 = 2x^2 + 3y^2\). 2. Simplify \(B\): \(B = 2x^2 + 2y^2 + y^2 = 2x^2 + 3y^2\). 3. Because both expressions simplify to \(2x^2 + 3y^2\), they are equivalent. 4. Substitute: \(2 \cdot (-5)^2 + 3 \cdot \left(\frac{1}{3}\right)^2 = 50 + \frac{1}{3} = \frac{151}{3}\).

Answer

a) Both expressions simplify to \(2x^2 + 3y^2\). b) \(\frac{151}{3}\), or \(50\frac{1}{3}\)
5233809
Combine like terms first, then divide and simplify. Assume \(a \ne 0\). \((-0.2a^3 + 0.5a^2 - 1.1a^2 + 0.04a) \div (-0.2a)\)

Hints

- Combine only terms with identical variable parts. - Divide each remaining term by the monomial. - Determine the sign, coefficient, and variable power separately.

Solution

1. Combine like terms: \(0.5a^2 - 1.1a^2 = -0.6a^2\). 2. The dividend becomes \(-0.2a^3 - 0.6a^2 + 0.04a\). 3. Divide each term by \(-0.2a\): \(a^2 + 3a - 0.2\).

Answer

\(a^2 + 3a - 0.2\)
5234259
Simplify the expression. \(3x(x - 4) - (6x^2 + 9x) \div 3\)

Hints

- Use the order of operations. - Divide each term inside the parentheses by \(3\). - A minus sign before parentheses changes both signs when the parentheses are removed. - Combine only terms with the same variable part.

Solution

1. Distribute: \(3x(x - 4) = 3x^2 - 12x\). 2. Divide each term: \((6x^2 + 9x) \div 3 = 2x^2 + 3x\). 3. Subtract and combine like terms: \(3x^2 - 12x - (2x^2 + 3x) = x^2 - 15x\).

Answer

\(x^2 - 15x\)
5237259
An open-top box is made from a square sheet of cardboard by cutting a \(4\,\text{in.}\)-by-\(4\,\text{in.}\) square from each corner and folding up the sides. The area of the box''s base is \(160\,\text{in.}^2\) less than the area of the original sheet. Find the side length of the original sheet and the volume of the box.

Hints

- Identify how the corner cutouts change each base dimension. - Subtract twice the cutout length from each original dimension. - Compare the area of the original sheet with the area of the box's base. - Use base area times height for the box's volume.

Solution

1. Let \(a\) inches be the side length of the original square sheet. Its area is \(a^2\). 2. Cutting \(4\,\text{in.}\) from both ends of each dimension leaves a square base with side length \(a - 8\). Its area is \((a - 8)^2\). 3. The area difference is \(160\,\text{in.}^2\), so \(a^2 - (a - 8)^2 = 160\). 4. Expand: \(a^2 - (a^2 - 16a + 64) = 160\). 5. Simplify: \(16a - 64 = 160\), so \(16a = 224\) and \(a = 14\). 6. The base is \(6\,\text{in.}\) by \(6\,\text{in.}\), and the height is \(4\,\text{in.}\). Thus, the volume is \(6 \cdot 6 \cdot 4 = 144\,\text{in.}^3\).

Answer

The original sheet has side length \(14\,\text{in.}\), and the box has volume \(144\,\text{in.}^3\).
5237539
A rectangular garden bed is \(8\,\text{m}\) longer than it is wide. For a redesign, the length is decreased by \(3\,\text{m}\), and the width is increased by \(3\,\text{m}\). By how many square meters does the area change?

Hints

- Let a variable represent the original width. - Write the original and new dimensions in terms of that variable. - Expand both area expressions. - Subtract the original area from the new area.

Solution

1. Let the original width be \(b\). Then the original length is \(b+8\), and the original area is \(A_1=b(b+8)=b^2+8b\). 2. The new width is \(b+3\), and the new length is \((b+8)-3=b+5\). 3. The new area is \(A_2=(b+3)(b+5)=b^2+8b+15\). 4. The change is \(A_2-A_1=(b^2+8b+15)-(b^2+8b)=15\). The area increases by \(15\,\text{m}^2\).

Answer

The area increases by \(15\,\text{m}^2\).
5237549
A rectangular parking lot is \(12\,\text{m}\) longer than it is wide. A second parking lot is square, and its side length is the mean of the rectangular lot's length and width. a) Let \(b\) represent the rectangular lot's width. Write an expression for the area of each parking lot. b) Which parking lot has the greater area, and what is the exact difference?

Hints

- The mean of two values is their sum divided by \(2\). - Express the square's side length in terms of \(b\). - Expand both area expressions before comparing. - Identify the term that differs between the two results.

Solution

1. The rectangular lot has width \(b\) and length \(b+12\), so \(A_R=b(b+12)=b^2+12b\). 2. The square's side length is the mean: \(s=\frac{b+(b+12)}{2}=b+6\). 3. Its area is \(A_S=(b+6)^2=b^2+12b+36\). 4. Since \(A_S-A_R=36\), the square lot has \(36\,\text{m}^2\) more area.

Answer

a) Rectangle: \(b(b+12)=b^2+12b\); square: \((b+6)^2=b^2+12b+36\) b) The square parking lot has \(36\,\text{m}^2\) more area.
5279389
Rewrite products using exponents, then combine like terms. 1) \(4 \cdot x \cdot x + x^2 - 2 \cdot x \cdot x\) 2) \(a \cdot a \cdot b + a^2b + a \cdot b \cdot b\) 3) \(3z^3 + z \cdot z \cdot z - 2z^3\) 4) \(2p^2 + q^3 + p \cdot p + q \cdot q \cdot q + p^2\)

Hints

- Terms are like terms only when all variable bases and exponents match. - A term without a written coefficient has coefficient \(1\). - Track subtraction signs carefully.

Solution

1. \(4x^2 + x^2 - 2x^2 = 3x^2\). 2. \(a^2b + a^2b + ab^2 = 2a^2b + ab^2\). 3. \(3z^3 + z^3 - 2z^3 = 2z^3\). 4. \(2p^2 + q^3 + p^2 + q^3 + p^2 = 4p^2 + 2q^3\).

Answer

1) \(3x^2\) 2) \(2a^2b + ab^2\) 3) \(2z^3\) 4) \(4p^2 + 2q^3\)
5279569
Lucas simplified \((15x^2-4x)-(7x^2-9x)\) and got \(8x^2-13x\). Explain Lucas's error and find the correct result.

Hints

- Check how each sign changes when the second polynomial is subtracted. - Subtracting a negative term produces a positive term. - Determine the sign of the \(9x\) term after removing the parentheses.

Solution

1. Lucas did not reverse the sign of \(-9x\) when subtracting the second polynomial. He treated \(-4x-9x\) as the linear part instead of \(-4x+9x\). 2. Subtract the second polynomial correctly: \((15x^2-4x)-(7x^2-9x)=15x^2-4x-7x^2+9x\). 3. Combine like terms: \(15x^2-7x^2=8x^2\) and \(-4x+9x=5x\). 4. The correct result is \(8x^2+5x\).

Answer

Lucas failed to change the sign of \(-9x\) when he subtracted the second polynomial. The correct result is \(8x^2+5x\).
5279759
A square has side length \(s\) inches. One side is increased by \(2\,\text{in.}\), and the other is increased by \(5\,\text{in.}\), forming a rectangle. The rectangle''s area is \(45\,\text{in.}^2\) greater than the square''s area. Find \(s\).

Hints

- Write the area of the square. - Express both rectangle dimensions in terms of \(s\). - Set the new area equal to the old area plus \(45\). - Expand the product and simplify.

Solution

1. The square's area is \(s^2\). 2. The rectangle has dimensions \(s + 2\) and \(s + 5\), so its area is \((s + 2)(s + 5)\). 3. Write the area equation: \((s + 2)(s + 5) = s^2 + 45\). 4. Expand: \(s^2 + 7s + 10 = s^2 + 45\). 5. Subtract \(s^2\): \(7s + 10 = 45\). 6. Subtract \(10\) and divide by \(7\): \(7s = 35\), so \(s = 5\).

Answer

The square''s side length is \(5\,\text{in.}\).
5279809
A rectangular garden is \(5\,\text{ft}\) longer than it is wide. If the width were increased by \(2\,\text{ft}\) while the length stayed the same, the area would increase by \(30\,\text{ft}^2\). Find the original dimensions by writing and solving an equation.

Hints

- Express the length in terms of the width. - Write area expressions before and after the width changes. - Subtract the original area from the new area. - Set the difference equal to \(30\).

Solution

1. Let \(b\) feet be the original width. The length is \(b + 5\) feet. 2. The original area is \(b(b + 5)\). 3. The new area is \((b + 2)(b + 5)\). 4. The increase is \(30\,\text{ft}^2\), so \((b + 2)(b + 5) - b(b + 5) = 30\). 5. Expand and simplify: \(b^2 + 7b + 10 - b^2 - 5b = 30\), so \(2b + 10 = 30\). 6. Subtract \(10\) and divide by \(2\): \(b = 10\). 7. The original length is \(10\,\text{ft} + 5\,\text{ft} = 15\,\text{ft}\).

Answer

The garden was originally \(10\,\text{ft}\) wide and \(15\,\text{ft}\) long.
5279889
Find the missing terms so the equation is true, assuming \(xy \ne 0\): \((\square - 12x^2y^2 + \square) \div 4xy = 2x^2 - 3xy + 5y^2\)

Hints

- Use multiplication as the inverse of division. - Multiply every term in the quotient by the divisor. - Use the given middle term to check the pattern.

Solution

1. Multiply each term on the right by \(4xy\). 2. The first missing term is \(2x^2(4xy) = 8x^3y\). 3. The middle term checks: \(-3xy(4xy) = -12x^2y^2\). 4. The final missing term is \(5y^2(4xy) = 20xy^3\). 5. Thus, \((8x^3y - 12x^2y^2 + 20xy^3) \div 4xy = 2x^2 - 3xy + 5y^2\).

Answer

The missing terms are \(8x^3y\) and \(20xy^3\).
5280709
Verify the identity by expanding and combining like terms. \((x + 3)(x^2 - 3x + 9) = x^3 + 27\)

Hints

- Multiply each term in the first factor by every term in the second factor. - Track the signs carefully. - Look for opposite terms that cancel.

Solution

1. Distribute: \((x + 3)(x^2 - 3x + 9) = x(x^2 - 3x + 9) + 3(x^2 - 3x + 9)\). 2. Multiply: \(x^3 - 3x^2 + 9x + 3x^2 - 9x + 27\). 3. The quadratic terms and linear terms cancel, leaving \(x^3 + 27\). Therefore, the identity is true.

Answer

The left side simplifies to \(x^3 + 27\), so the identity is verified.
5290549
Determine which functions are polynomial functions. For each polynomial, state its degree and leading coefficient. a) \(g_1(x)=0.2x^3-x^2+5\) b) \(g_2(x)=\frac{1}{x^2+1}\) c) \(g_3(x)=(x^2-1)(2-x)\) d) \(g_4(x)=3^x-3x\) e) \(g_5(x)=\frac{x^4}{8}-\pi x\)

Hints

- Check the exponents of \(x\). - Expand products before identifying degree and leading coefficient. - Distinguish a power function from an exponential function. - Real coefficients may include fractions and irrational numbers.

Solution

1. A polynomial has real coefficients and only nonnegative integer powers of \(x\). 2. For a), the highest power is \(3\), so it is a degree-\(3\) polynomial with leading coefficient \(0.2\). 3. For b), the variable appears in a denominator, so the function is not polynomial. 4. For c), expand: \((x^2-1)(2-x)=-x^3+2x^2+x-2\). It is degree \(3\) with leading coefficient \(-1\). 5. For d), \(3^x\) is exponential, so the function is not polynomial. 6. For e), \(g_5(x)=\frac{1}{8}x^4-\pi x\). It is degree \(4\) with leading coefficient \(\frac{1}{8}\).

Answer

a) Polynomial; degree \(3\); leading coefficient \(0.2\) b) Not polynomial c) Polynomial; degree \(3\); leading coefficient \(-1\) d) Not polynomial e) Polynomial; degree \(4\); leading coefficient \(\frac{1}{8}\)
5125649
A rectangular sign is twice as long as it is tall. If its height is increased by \(3\,\text{in.}\) and its length is decreased by \(2\,\text{in.}\), its area increases by \(30\,\text{in.}^2\). Find the sign''s original height and length.

Hints

- Express the original length in terms of the height. - Write the original and new area expressions. - Set the new area equal to the original area plus \(30\). - Expand the product and simplify; the quadratic terms will cancel.

Solution

1. Let \(x\) inches be the original height. The original length is \(2x\), so the original area is \(2x^2\). 2. The new height is \(x + 3\), and the new length is \(2x - 2\). 3. The new area is \((x + 3)(2x - 2) = 2x^2 + 4x - 6\). 4. The area increases by \(30\), so \(2x^2 + 4x - 6 = 2x^2 + 30\). 5. Subtract \(2x^2\): \(4x - 6 = 30\). Add \(6\): \(4x = 36\). Divide by \(4\): \(x = 9\). 6. The original height was \(9\,\text{in.}\), and the original length was \(18\,\text{in.}\).

Answer

The original dimensions were \(9\,\text{in.}\) by \(18\,\text{in.}\).
5137529
One side of a rectangle is exactly \(5\,\text{in.}\) longer than the other side. If the longer side is increased by \(2\,\text{in.}\) and the shorter side is increased by \(3\,\text{in.}\), the area increases by \(66\,\text{in.}^2\). Find the original side lengths.

Hints

- Represent the shorter side with a variable and express the longer side in terms of it. - Write expressions for the original and new areas. - Set the new area equal to the original area plus \(66\). - Expand both products and check whether the quadratic terms cancel.

Solution

1. Let \(x\) inches be the shorter side. The longer side is \(x + 5\) inches. 2. The original area is \(x(x + 5)\). 3. The new side lengths are \(x + 3\) and \(x + 7\), so the new area is \((x + 3)(x + 7)\). 4. The area increases by \(66\,\text{in.}^2\), so \((x + 3)(x + 7) = x(x + 5) + 66\). 5. Expand: \(x^2 + 10x + 21 = x^2 + 5x + 66\). 6. Subtract \(x^2\) and solve: \(10x + 21 = 5x + 66\), so \(5x = 45\) and \(x = 9\). 7. The longer side is \(9\,\text{in.} + 5\,\text{in.} = 14\,\text{in.}\).

Answer

The original side lengths are \(9\,\text{in.}\) and \(14\,\text{in.}\).
5230549
Fill in each blank so the equation is true. a) \(\underline{\hspace{1cm}}(3x - 4y) = 12x^2 - 16xy\) b) \(-5b(2a + \underline{\hspace{1cm}}) = -10ab - 15b^2\) c) \(x(\underline{\hspace{1cm}} - 7) = x^2 - 7x\)

Hints

- Work backward from a product term to its missing factor. - Division is the inverse of multiplication. - Check both the sign and the exponent of each missing term.

Solution

1. For a), divide the first product term by \(3x\): \(12x^2 \div 3x = 4x\). Checking gives \(4x(-4y) = -16xy\). 2. For b), divide the second product term by \(-5b\): \(-15b^2 \div (-5b) = 3b\). 3. For c), divide \(x^2\) by \(x\): \(x^2 \div x = x\).

Answer

a) \(4x\) b) \(3b\) c) \(x\)
5230609
A polynomial was multiplied by \(4a^2\), producing \(12a^3 - 8a^2b + 20a^2\). a) Find the original polynomial. b) Find the result if the original polynomial is multiplied by \(-2ab\) instead.

Hints

- Divide each product term by \(4a^2\) to recover the corresponding term in the polynomial. - Division reverses multiplication. - For part b), distribute \(-2ab\) to every term in the polynomial. - Check signs and exponents carefully.

Solution

1. Divide each term by \(4a^2\): \(12a^3 \div 4a^2 = 3a\), \(-8a^2b \div 4a^2 = -2b\), and \(20a^2 \div 4a^2 = 5\). The original polynomial is \(3a - 2b + 5\). 2. Multiply by \(-2ab\): \(-2ab(3a - 2b + 5) = -6a^2b + 4ab^2 - 10ab\).

Answer

a) \(3a - 2b + 5\) b) \(-6a^2b + 4ab^2 - 10ab\)
5231149
Expand and simplify. \(\left(\frac{1}{2}x + \frac{1}{3}y - \frac{1}{4}z\right)\left(\frac{1}{2}x - \frac{1}{3}y + \frac{1}{4}z\right)\)

Hints

- Multiply every term in the first trinomial by every term in the second. - Apply the sign rules carefully. - Look for pairs of opposite terms after expanding. - Add fractions with the same denominator directly.

Solution

1. Form the nine partial products: \(\frac{1}{4}x^2 - \frac{1}{6}xy + \frac{1}{8}xz + \frac{1}{6}xy - \frac{1}{9}y^2 + \frac{1}{12}yz - \frac{1}{8}xz + \frac{1}{12}yz - \frac{1}{16}z^2\). 2. The \(xy\)-terms and \(xz\)-terms cancel. The \(yz\)-terms combine to \(\frac{1}{6}yz\). 3. The result is \(\frac{1}{4}x^2 - \frac{1}{9}y^2 + \frac{1}{6}yz - \frac{1}{16}z^2\).

Answer

\(\frac{1}{4}x^2 - \frac{1}{9}y^2 + \frac{1}{6}yz - \frac{1}{16}z^2\)
5231169
Let \(T(n) = (3n - 2)(n + 3) - (n - 1)(3n + 2) + (n + 2)(n - 2) - n^2\). Simplify the expression first, then evaluate it for \(n = -1\frac{1}{8}\).

Hints

- Break the expression into separate products and simplify each one. - One product is a difference of squares. - Pay close attention to the minus sign before the second product. - Convert the mixed number to an improper fraction before evaluating.

Solution

1. Expand the products: \((3n - 2)(n + 3) = 3n^2 + 7n - 6\), \((n - 1)(3n + 2) = 3n^2 - n - 2\), and \((n + 2)(n - 2) = n^2 - 4\). 2. Substitute these expressions and combine like terms: \((3n^2 + 7n - 6) - (3n^2 - n - 2) + (n^2 - 4) - n^2 = 8n - 8\). 3. Convert \(-1\frac{1}{8}\) to \(-\frac{9}{8}\), then evaluate: \(8 \cdot \left(-\frac{9}{8}\right) - 8 = -17\).

Answer

Simplified expression: \(8n - 8\) Value at \(n = -1\frac{1}{8}\): \(-17\)
5231669
The product of two consecutive odd integers is \(48\) less than the product of the next two consecutive odd integers. Find the four integers.

Hints

- Consecutive odd integers differ by \(2\). - Write one product for each pair of odd integers. - Expand both products and distribute the subtraction carefully. - Observe what happens to the \(x^2\) terms.

Solution

1. Let \(x\) be the first odd integer. The next three are \(x + 2\), \(x + 4\), and \(x + 6\). 2. Write the product-difference equation \((x + 4)(x + 6) - x(x + 2) = 48\). 3. Expand both products: \(x^2 + 10x + 24 - (x^2 + 2x) = 48\). 4. Distribute the subtraction and combine like terms: \(x^2 + 10x + 24 - x^2 - 2x = 48\), so \(8x + 24 = 48\). 5. Subtract \(24\): \(8x = 24\). Divide by \(8\): \(x = 3\). 6. The four integers are \(3\), \(5\), \(7\), and \(9\).

Answer

The four odd integers are \(3\), \(5\), \(7\), and \(9\).
5231759
1. Simplify the expression and show that its value does not depend on \(n\): \((n + 3)(n + 4) - (n + 1)(n + 6)\). 2. Solve the equation: \((2x + 1)(3x - 2) - 6(x - 1)(x + 2) = 31\).

Hints

- Expand each product using the distributive property. - A minus sign before parentheses changes every sign inside. - After simplifying the equation, isolate the variable term. - An expression independent of a variable simplifies to a constant.

Solution

1. Expand and subtract: \((n^2 + 7n + 12) - (n^2 + 7n + 6) = 6\). Since \(n\) cancels, the value is independent of \(n\). 2. Expand both products: \((2x + 1)(3x - 2) = 6x^2 - x - 2\) and \((x - 1)(x + 2) = x^2 + x - 2\). 3. Substitute and simplify: \(6x^2 - x - 2 - 6(x^2 + x - 2) = 31\), so \(-7x + 10 = 31\). 4. Solve: \(-7x = 21\), so \(x = -3\).

Answer

1) \(6\) 2) \(x = -3\)
5231789
A square playground is redesigned as a rectangle by increasing one side by \(6\,\text{ft}\) and decreasing the other side by \(4\,\text{ft}\). The new area is \(16\,\text{ft}^2\) greater than the original area. a) Find the original side length of the square. b) Someone claims, “If one side is increased by the same amount that the other side is decreased, the area always stays the same.” Use the side length from part a) and changes of \(5\,\text{ft}\) to show that the claim is false.

Hints

- Write area expressions for the square and the redesigned rectangle. - The quadratic terms should cancel when you compare the areas. - For part b), calculate both areas using the value from part a). - A single counterexample is enough to disprove an “always” claim.

Solution

1. Let \(s\) feet be the square's side length. Its area is \(s^2\). 2. The redesigned rectangle has dimensions \(s + 6\) and \(s - 4\), so its area is \((s + 6)(s - 4) = s^2 + 2s - 24\). 3. The new area is \(16\,\text{ft}^2\) greater, so \(s^2 + 2s - 24 = s^2 + 16\). 4. Subtract \(s^2\) and solve: \(2s - 24 = 16\), so \(2s = 40\) and \(s = 20\). 5. For part b), the original area is \(20 \cdot 20 = 400\,\text{ft}^2\). 6. Changing the sides by \(5\,\text{ft}\) gives dimensions \(25\,\text{ft}\) and \(15\,\text{ft}\), with area \(25 \cdot 15 = 375\,\text{ft}^2\). 7. Since \(375 \neq 400\), the claim is false.

Answer

a) The original side length was \(20\,\text{ft}\). b) The changed dimensions are \(25\,\text{ft}\) by \(15\,\text{ft}\), with area \(375\,\text{ft}^2\), not \(400\,\text{ft}^2\). Therefore, the claim is false.
5233089
Examine the accuracy of \((1 + a)(1 + b) \approx 1 + a + b\) in these cases: Case I: \(1.003 \cdot 1.003\) Case II: \(1.003 \cdot 0.997\) a) Find both approximate values. b) Find both exact products. c) Compare the absolute errors. Explain your observation using the omitted term \(ab\).

Hints

- In Case II, the second number is less than \(1\), so \(b\) is negative. - Compare the exact expansion with the approximation to identify the error term. - Compute the absolute difference between each estimate and exact product.

Solution

1. Case I has \(a = 0.003\), \(b = 0.003\), so the estimate is \(1.006\). 2. Case II has \(a = 0.003\), \(b = -0.003\), so the estimate is \(1.000\). 3. The exact products are \(1.003 \cdot 1.003 = 1.006009\) and \(1.003 \cdot 0.997 = 0.999991\). 4. Each absolute error is \(0.000009\). The omitted products are \(0.003 \cdot 0.003 = 0.000009\) and \(0.003 \cdot (-0.003) = -0.000009\), which have the same absolute value.

Answer

a) Case I: \(1.006\); Case II: \(1.000\) b) Case I: \(1.006009\); Case II: \(0.999991\) c) Both absolute errors are \(0.000009\) because the omitted terms \(ab\) have equal absolute values.
5237269
A rectangular sheet of cardboard is exactly twice as long as it is wide. An open-top box is made by cutting a \(2\,\text{in.}\)-by-\(2\,\text{in.}\) square from each corner and folding up the sides. The original sheet has \(44\,\text{in.}^2\) more area than the box''s base. Find the original dimensions and the volume of the box.

Hints

- Express the length in terms of the width. - Each base dimension is reduced by twice the cutout length. - Compare the original area with the base area. - Check that the resulting base dimensions are positive before finding the volume.

Solution

1. Let \(b\) inches be the width. The length is \(2b\), so the original area is \(2b^2\). 2. The box's base has dimensions \(2b - 4\) and \(b - 4\), so its area is \((2b - 4)(b - 4)\). 3. Expand the base area: \((2b - 4)(b - 4) = 2b^2 - 12b + 16\). 4. The area difference is \(44\,\text{in.}^2\), so \(2b^2 - (2b^2 - 12b + 16) = 44\). 5. Simplify: \(12b - 16 = 44\), so \(12b = 60\) and \(b = 5\). 6. The original sheet is \(5\,\text{in.}\) by \(10\,\text{in.}\). The base is \(1\,\text{in.}\) by \(6\,\text{in.}\), and the height is \(2\,\text{in.}\). 7. The volume is \(1 \cdot 6 \cdot 2 = 12\,\text{in.}^3\).

Answer

The original sheet is \(5\,\text{in.}\) by \(10\,\text{in.}\), and the box has volume \(12\,\text{in.}^3\).

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