Aimathic
Login | English | Deutsch

Free Math Worksheets

Build your own math worksheets from 21,000 problems for grades 3 to 12, from fractions to calculus. Every problem includes step-by-step solutions.

Combine like terms

Click problems to add them to your worksheet.

5228036
Find each sum and simplify. a) \(12a\) and \(5a\) b) \(4x\) and \(-9x\) c) \(-3m\) and \(3m\) d) \(7y\) and \(2z\)

Hints

- Like terms have the same variable part. - Add the coefficients of like terms. - Unlike terms cannot be combined.

Solution

1. \(12a+5a=17a\). 2. \(4x+(-9x)=-5x\). 3. \(-3m+3m=0\). 4. The terms \(7y\) and \(2z\) are not like terms, so their sum remains \(7y+2z\).

Answer

a) \(17a\) b) \(-5x\) c) \(0\) d) \(7y+2z\)
5228056
Combine like terms. a) \(-8x+(-5x)\) b) \(14y-20y\) c) \(-11a+11a\) d) \(3c-(-7c)\)

Hints

- Add the signed coefficients. - Opposite terms cancel. - Subtracting a negative term is the same as adding a positive term.

Solution

1. \(-8x+(-5x)=(-8-5)x=-13x\). 2. \(14y-20y=(14-20)y=-6y\). 3. \(-11a+11a=0\). 4. \(3c-(-7c)=3c+7c=10c\).

Answer

a) \(-13x\) b) \(-6y\) c) \(0\) d) \(10c\)
5124756
Combine like terms. a) \(1.5a+2.7a-0.8a\) b) \(-3k-4k+12k-k\) c) \(\frac{1}{2}x+\frac{3}{4}x-x\) d) \(12y-15y+3y\)

Hints

- Combine only terms with the same variable part. - A variable with no visible coefficient has coefficient \(1\). - Work with the numerical coefficients while keeping each sign.

Solution

1. For part a, combine the coefficients: \(1.5+2.7-0.8=3.4\), so the result is \(3.4a\). 2. For part b, \(-3-4+12-1=4\), so the result is \(4k\). 3. For part c, \(\frac{1}{2}+\frac{3}{4}-1=\frac{2}{4}+\frac{3}{4}-\frac{4}{4}=\frac{1}{4}\), so the result is \(\frac{1}{4}x\). 4. For part d, \(12-15+3=0\), so all variable terms cancel and the result is \(0\).

Answer

a) \(3.4a\) b) \(4k\) c) \(\frac{1}{4}x\) d) \(0\)
5124776
Find the expression that belongs in each blank. a) \(5m+\underline{\hspace{1cm}}=12m\) b) \(8.4t-\underline{\hspace{1cm}}=2.1t\) c) \(-3b+\underline{\hspace{1cm}}=0\) d) \(\underline{\hspace{1cm}}-6p=-10p\)

Hints

- Treat each blank as a missing term in an addition or subtraction statement. - Use an inverse operation to find the missing term. - Keep careful track of negative signs.

Solution

1. For part a, subtract the known term from the result: \(12m-5m=7m\). 2. For part b, the missing term is \(8.4t-2.1t=6.3t\). 3. For part c, add the opposite of \(-3b\), which is \(3b\). 4. For part d, add \(6p\) to the result: \(-10p+6p=-4p\).

Answer

a) \(7m\) b) \(6.3t\) c) \(3b\) d) \(-4p\)
5154786
Combine like terms. \(12m-5n+3m-8n+13n\)

Hints

- Group terms that contain the same variable. - Keep each coefficient’s sign. - Terms cancel when their coefficients add to zero.

Solution

1. Combine the \(m\)-terms: \(12m+3m=15m\). 2. Combine the \(n\)-terms: \(-5n-8n+13n=(-5-8+13)n=0n\). 3. Therefore, the expression simplifies to \(15m\).

Answer

\(15m\)
5223396
Combine like terms. 1) \(a+a+a+a\) 2) \(10x-4x+5y+y\) 3) \(\frac{z}{6}+\frac{z}{6}+\frac{z}{6}+\frac{z}{6}+\frac{z}{6}\)

Hints

- Count how many copies of each variable are present. - Combine only terms with the same variable part. - Fractions with the same denominator are added by adding their numerators.

Solution

1. Four equal \(a\)-terms combine to \(4a\). 2. Combine each variable separately: \(10x-4x=6x\) and \(5y+y=6y\). The result is \(6x+6y\). 3. Add the fractions with the same denominator: \(\frac{z+z+z+z+z}{6}=\frac{5z}{6}\).

Answer

1) \(4a\) 2) \(6x+6y\) 3) \(\frac{5z}{6}\)
5223406
Combine like terms. 1) \(6.4m-2.1m+3.5n-n\) 2) \(\frac{c}{3}+\frac{c}{3}+\frac{c}{3}-\frac{d}{2}-\frac{d}{2}\) 3) \(\frac{2}{9}k+\frac{7}{9}k-k\)

Hints

- Combine only terms with the same variable part. - Work with the numerical coefficients. - A variable with no visible coefficient has coefficient \(1\).

Solution

1. Combine each variable separately: \(6.4m-2.1m=4.3m\) and \(3.5n-n=2.5n\). The result is \(4.3m+2.5n\). 2. Three copies of \(\frac{c}{3}\) equal \(c\), and two copies of \(\frac{d}{2}\) equal \(d\). The result is \(c-d\). 3. \(\frac{2}{9}k+\frac{7}{9}k=k\), so \(k-k=0\).

Answer

1) \(4.3m+2.5n\) 2) \(c-d\) 3) \(0\)
5223496
Write each sum more concisely by using coefficients and combining like terms. 1) \(uv+uv+uv+uv\) 2) \(xyz+xyz+xyz\) 3) \(a+a-b-b-b\)

Hints

- Count the number of identical terms. - Keep each term’s sign. - Only terms with identical variable parts can be combined.

Solution

1. Four identical \(uv\)-terms combine to \(4uv\). 2. Three identical \(xyz\)-terms combine to \(3xyz\). 3. Two positive \(a\)-terms combine to \(2a\), and three negative \(b\)-terms combine to \(-3b\). The result is \(2a-3b\).

Answer

1) \(4uv\) 2) \(3xyz\) 3) \(2a-3b\)
5227636
Combine like terms. 1) \(1.5x+3.2x-0.7x\) 2) \(-4y-(-7y)\) 3) \(12a-15a+3a\)

Hints

- Combine the numerical coefficients of like terms. - Subtracting a negative term changes to addition. - A term with coefficient zero has value zero.

Solution

1. Combine the coefficients: \(1.5+3.2-0.7=4\). The result is \(4x\). 2. Subtracting a negative term is addition: \(-4y-(-7y)=-4y+7y=3y\). 3. Combine the coefficients: \(12-15+3=0\). Therefore, the expression equals \(0\).

Answer

1) \(4x\) 2) \(3y\) 3) \(0\)
5227646
Find the expression that belongs in each box. 1) \(7b-\Box=-3b\) 2) \(\Box+(-5k)=2k\) 3) \(4m-9m+\Box=0\)

Hints

- Treat each box as an unknown term. - Use inverse operations to isolate the missing term. - To make a sum equal zero, add the opposite term.

Solution

1. The missing subtracted term is \(7b-(-3b)=10b\). Check: \(7b-10b=-3b\). 2. Subtract \(-5k\) from \(2k\): \(2k-(-5k)=7k\). Check: \(7k+(-5k)=2k\). 3. First combine \(4m-9m=-5m\). Its opposite, \(5m\), must be added to obtain \(0\).

Answer

1) \(10b\) 2) \(7k\) 3) \(5m\)
5227886
Combine like terms. \(4.7m-2.15n+1.3m-3.85n-5.2m\)

Hints

- Group terms containing the same variable. - Align decimal points when combining coefficients. - Keep the negative signs on the \(n\)-terms.

Solution

1. Combine the \(m\)-terms: \(4.7+1.3-5.2=0.8\). 2. Combine the \(n\)-terms: \(-2.15-3.85=-6\). 3. The simplified expression is \(0.8m-6n\).

Answer

\(0.8m-6n\)
5228046
Find the missing expression in each equation. a) \(8x+\underline{\hspace{1cm}}=15x\) b) \(5a+\underline{\hspace{1cm}}=-2a\) c) \(\underline{\hspace{1cm}}+(-4m)=6m\) d) \(3b+\underline{\hspace{1cm}}=3b-2c\)

Hints

- Use subtraction to find a missing addend. - Treat each variable term like a signed quantity. - Compare matching terms on both sides.

Solution

1. For part a, \(15x-8x=7x\). 2. For part b, \(-2a-5a=-7a\). 3. For part c, \(6m-(-4m)=10m\). 4. For part d, \(3b\) already appears on both sides, so the missing expression is \(-2c\).

Answer

a) \(7x\) b) \(-7a\) c) \(10m\) d) \(-2c\)
5228066
Find the missing expression in each equation. a) \(-5b+\underline{\hspace{1cm}}=2b\) b) \(12k-\underline{\hspace{1cm}}=-3k\) c) \(\underline{\hspace{1cm}}+(-8m)=-10m\)

Hints

- Use inverse operations to isolate the missing expression. - Keep track of negative signs. - Substitute each result to check the equation.

Solution

1. For part a, \(2b-(-5b)=7b\). 2. For part b, the amount subtracted is \(12k-(-3k)=15k\). 3. For part c, \(-10m-(-8m)=-2m\).

Answer

a) \(7b\) b) \(15k\) c) \(-2m\)
5228076
Combine like terms. \(14x-8y+3-5x+2y-11\)

Hints

- Group terms with the same variable. - Combine constant terms separately. - Keep each term’s sign.

Solution

1. Combine the \(x\)-terms: \(14x-5x=9x\). 2. Combine the \(y\)-terms: \(-8y+2y=-6y\). 3. Combine the constants: \(3-11=-8\). 4. The simplified expression is \(9x-6y-8\).

Answer

\(9x-6y-8\)
5228536
Combine like terms. \(\frac{3}{8}x-\frac{1}{3}y+\frac{1}{4}x-\frac{5}{6}y+x\)

Hints

- Group terms containing the same variable. - An \(x\) with no visible coefficient has coefficient \(1\). - Use common denominators when combining fractional coefficients.

Solution

1. Combine the \(x\)-coefficients: \(\frac{3}{8}+\frac{1}{4}+1=\frac{3}{8}+\frac{2}{8}+\frac{8}{8}=\frac{13}{8}\). 2. Combine the \(y\)-coefficients: \(-\frac{1}{3}-\frac{5}{6}=-\frac{2}{6}-\frac{5}{6}=-\frac{7}{6}\). 3. The simplified expression is \(\frac{13}{8}x-\frac{7}{6}y\).

Answer

\(\frac{13}{8}x-\frac{7}{6}y\)
5229006
A student claims, “When I add \(3a-5\), \(2-4a\), and \(a+3\), the variable \(a\) disappears completely.” Check the claim by adding and simplifying the three expressions. What is the result?

Hints

- Combine all \(a\)-terms separately from the constants. - A variable term disappears when its coefficient is zero. - Check whether the constants also cancel.

Solution

1. Write the sum: \((3a-5)+(2-4a)+(a+3)\). 2. Combine the variable terms: \(3a-4a+a=0\). 3. Combine the constants: \(-5+2+3=0\). 4. The total is \(0\), so the claim is correct.

Answer

The claim is correct. The sum is \(0\).
5229466
Find the expression that belongs in each box. 1) \(7x-\Box=15x\) 2) \(-4y-\Box=-10y\) 3) \(\Box-(-3z)=-z\) 4) \(\Box+(-8w)=2w\)

Hints

- Treat the box as an unknown term. - Use inverse operations to isolate it. - Substitute your result to check each equation.

Solution

1. Solve \(7x-M=15x\): \(M=7x-15x=-8x\). 2. Solve \(-4y-M=-10y\): \(M=-4y-(-10y)=6y\). 3. Solve \(M-(-3z)=-z\): \(M+3z=-z\), so \(M=-4z\). 4. Solve \(M+(-8w)=2w\): \(M=2w-(-8w)=10w\).

Answer

1) \(-8x\) 2) \(6y\) 3) \(-4z\) 4) \(10w\)
5229496
Combine like terms. 1) \(\frac{3}{5}a-(-a)\) 2) \(-\frac{1}{2}b-\left(-\frac{3}{4}b\right)\) 3) \(1\frac{2}{3}c-\left(-\frac{5}{6}c\right)\)

Hints

- Subtracting a negative term changes to addition. - Convert whole or mixed-number coefficients to fractions. - Use common denominators.

Solution

1. \(\frac{3}{5}a-(-a)=\frac{3}{5}a+a=\frac{8}{5}a\). 2. \(-\frac{1}{2}b-\left(-\frac{3}{4}b\right)=-\frac{2}{4}b+\frac{3}{4}b=\frac{1}{4}b\). 3. Convert \(1\frac{2}{3}\) to \(\frac{5}{3}\): \(\frac{5}{3}c+\frac{5}{6}c=\frac{10}{6}c+\frac{5}{6}c=\frac{5}{2}c\).

Answer

1) \(\frac{8}{5}a\) 2) \(\frac{1}{4}b\) 3) \(\frac{5}{2}c\)
5122486
First combine like terms. Then evaluate the expression for \(x=-1.2\). \(15x-7+5x+17\)

Hints

- Group the variable terms and constant terms separately. - Simplify the expression before substituting. - Use parentheses around the negative value when substituting.

Solution

1. Combine the variable terms: \(15x+5x=20x\). 2. Combine the constant terms: \(-7+17=10\). 3. The simplified expression is \(20x+10\). 4. Substitute \(x=-1.2\): \(20\times(-1.2)+10\). 5. Evaluate: \(-24+10=-14\).

Answer

\(-14\)
5124506
Let \(k\) be a positive integer. Consider the expressions Expression A: \(3k+1\) Expression B: \(2k+2\) a) Is Expression A greater than Expression B for every value of \(k\)? Explain. b) Explain algebraically why \(k+k+k\) is always a multiple of \(3\).

Hints

- Compare the expressions when \(k=1\). - How can repeated addition of the same quantity be written as multiplication? - What algebraic form guarantees that a number is a multiple of \(3\)?

Solution

1. For \(k=1\), Expression A is \(3\times1+1=4\), and Expression B is \(2\times1+2=4\). Since the expressions are equal for this value, Expression A is not greater for every positive integer \(k\). 2. More generally, the difference is \((3k+1)-(2k+2)=k-1\), which equals \(0\) when \(k=1\) and is positive when \(k>1\). 3. Combine like terms: \(k+k+k=3k\). Because \(3k\) is \(3\) times an integer, it is always a multiple of \(3\).

Answer

a) No. When \(k=1\), both expressions equal \(4\); Expression A is greater only when \(k>1\). b) Since \(k+k+k=3k\), the value always has a factor of \(3\) and is therefore a multiple of \(3\).
5124766
Anna and Ben combine like terms in \(7x-4x+x\). Anna says, “The result is \(3x\).” Ben says, “The result is \(4x\).” Who is correct? Show the calculation and explain the likely error in the other student’s reasoning.

Hints

- Write the implied coefficient of the final \(x\). - Combine all three coefficients, not only the first two. - Check how adding one more \(x\) changes \(3x\).

Solution

1. The coefficients are \(7\), \(-4\), and \(1\) because \(x=1x\). 2. Combine them: \(7-4+1=4\). 3. Therefore, the expression simplifies to \(4x\), so Ben is correct. 4. Anna likely ignored the implied coefficient \(1\) on the final \(x\) and stopped after calculating \(7-4=3\).

Answer

Ben is correct: \(7x-4x+x=(7-4+1)x=4x\). Anna likely overlooked the coefficient \(1\) on the final \(x\).
5124816
Simplify each expression, then evaluate it for the given variable value. a) \(6x\times2-4x+9\) for \(x=-4\) b) \(3.5-8y+1.2-y\) for \(y=0.5\)

Hints

- Perform multiplication before addition or subtraction. - Combine variable terms and constants separately. - A term written as \(-y\) has coefficient \(-1\).

Solution

1. For part a, multiply first and combine like terms: \(6x\times2-4x+9=12x-4x+9=8x+9\). 2. Substitute \(x=-4\): \(8\times(-4)+9=-32+9=-23\). 3. For part b, combine the constants and variable terms: \(3.5-8y+1.2-y=4.7-9y\). 4. Substitute \(y=0.5\): \(4.7-9\times0.5=4.7-4.5=0.2\).

Answer

a) Simplified expression: \(8x+9\); value: \(-23\) b) Simplified expression: \(4.7-9y\); value: \(0.2\)
5124856
Combine like terms. a) \(A=15x-4\times2x-7x\) b) \(B=1.2z+0.8z-3\times0.5z\) Then evaluate \(B\) for \(z=-4\).

Hints

- Perform each multiplication before combining like terms. - Variable terms can cancel completely. - Substitute the given value only after simplifying \(B\).

Solution

1. Simplify \(A\): \(15x-4\times2x-7x=15x-8x-7x=0\). 2. Simplify \(B\): \(3\times0.5z=1.5z\), so \(B=1.2z+0.8z-1.5z=0.5z\). 3. Evaluate \(B\) at \(z=-4\): \(0.5\times(-4)=-2\).

Answer

a) \(A=0\) b) \(B=0.5z\) For \(z=-4\), \(B=-2\).
5223506
Simplify each expression. 1) \((c-d)+(c-d)+(c-d)\) 2) \(\frac{pq+pq+pq+pq+pq+pq}{9}\) 3) Subtract \(2ab\) from the sum \(ab+ab+ab+ab+ab\).

Hints

- Count how many times the entire grouped expression appears. - Combine the terms in the numerator before simplifying the fraction. - Rewrite repeated equal terms using a coefficient.

Solution

1. Three identical grouped expressions combine to \(3(c-d)\), which can also be written as \(3c-3d\). 2. The numerator contains six \(pq\)-terms, so \(\frac{pq+pq+pq+pq+pq+pq}{9}=\frac{6pq}{9}=\frac{2}{3}pq\). 3. The sum of five \(ab\)-terms is \(5ab\). Then \(5ab-2ab=3ab\).

Answer

1) \(3(c-d)\), or \(3c-3d\) 2) \(\frac{2}{3}pq\) 3) \(3ab\)
5223946
In algebra, a number can serve as a coefficient or an exponent. a) Explain the difference between \(4x\) and \(x^4\) by writing \(4x\) as repeated addition and \(x^4\) as repeated multiplication. b) Use repeated addition, without coefficients, to show that \(2a+3a=5a\). c) Use repeated addition to explain why \(3x+2y\) cannot be combined into one term such as \(5xy\).

Hints

- A coefficient tells how many copies are added; an exponent tells how many equal factors are multiplied. - Expand each coefficient into repeated addition. - Can terms with different variable parts be counted as copies of the same quantity? - Count the total number of \(a\)-terms in part b).

Solution

1. The coefficient \(4\) in \(4x\) counts four addends: \(x+x+x+x\). The exponent \(4\) in \(x^4\) counts four factors: \(x\times x\times x\times x\). 2. Write \(2a+3a\) as \((a+a)+(a+a+a)\). This is \(a+a+a+a+a=5a\). 3. Write \(3x+2y\) as \(x+x+x+y+y\). The \(x\)-terms and \(y\)-terms are unlike terms, so they cannot be combined into a single term.

Answer

a) \(4x=x+x+x+x\), while \(x^4=x\times x\times x\times x\). b) \(2a+3a=(a+a)+(a+a+a)=a+a+a+a+a=5a\). c) \(3x+2y=x+x+x+y+y\). Since \(x\) and \(y\) are different variables, the terms are not like terms and cannot be combined.
5229506
Combine like terms and give each result as a fraction in simplest form. 1) \(\frac{4}{9}x-\frac{5}{6}x-\left(-\frac{1}{3}x\right)\) 2) Find the expression that belongs in the blank: \(\frac{7}{10}y-\underline{\hspace{1cm}}=-\frac{1}{5}y\)

Hints

- Use a common denominator for all fractional coefficients. - Treat the blank as an unknown expression. - Pay close attention to subtraction of a negative term.

Solution

1. Use denominator \(18\): \(\frac{8}{18}x-\frac{15}{18}x+\frac{6}{18}x=-\frac{1}{18}x\). 2. Let the missing expression be \(M\). Then \(M=\frac{7}{10}y-\left(-\frac{1}{5}y\right)=\frac{7}{10}y+\frac{2}{10}y=\frac{9}{10}y\).

Answer

1) \(-\frac{1}{18}x\) 2) \(\frac{9}{10}y\)

All problems may be used, copied and printed free of charge for school and tutoring, including paid tutoring. Commercial adaptations as well as publication or redistribution on the internet are not permitted.