Expressions and Equations: Practice Questions with Answers

Curriculum: Expressions And EquationsGrades: 6–8Questions: 12Mode: Practice

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1. In the expression 3x + 5, what is x called?

A constant
A coefficient
An operator
A variable

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Answer: D. A variable
A variable is a letter that stands for a number that can change, like x in this expression.

2. Evaluate the expression 3x + 2 when x = 4.

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Answer: D. 14
Substitute 4 for x: 3(4) + 2 = 12 + 2 = 14.

3. In the term 7y, what is the coefficient?

y
7y
7
There is no coefficient

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Answer: C. 7
The coefficient is the number multiplied by the variable, so in 7y the coefficient is 7.

4. What is the constant in the expression 5x + 9?

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Answer: C. 9
A constant is a term that does not change and has no variable attached, so 9 is the constant.

5. Which expression represents '5 more than a number n'?

5/n
n + 5
n - 5
5n

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Answer: B. n + 5
'More than' means addition, so 5 more than n is written as n + 5.

6. Simplify: 4x + 3x

x
12x
7x
7x^2

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Answer: C. 7x
Since 4x and 3x are like terms (same variable), add their coefficients: 4 + 3 = 7, giving 7x.

7. Simplify: 2x + 5 + 3x + 1

10x
5x + 6
5x + 5
6x + 5

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Answer: B. 5x + 6
Combine the like terms: 2x + 3x = 5x, and 5 + 1 = 6, so the simplified expression is 5x + 6.

8. Solve for x: x + 6 = 10

x = 16
x = -4
x = 4
x = 6

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Answer: C. x = 4
To undo adding 6, subtract 6 from both sides: x = 10 - 6 = 4.

9. Solve for x: x - 4 = 9

x = -5
x = 13
x = 36
x = 5

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Answer: B. x = 13
To undo subtracting 4, add 4 to both sides: x = 9 + 4 = 13.

10. Solve for x: 3x = 12

x = 15
x = 4
x = 36
x = 9

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Answer: B. x = 4
To undo multiplying by 3, divide both sides by 3: x = 12 / 3 = 4.

11. Solve for x: x/2 = 5

x = 10
x = 2.5
x = 7
x = 3

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Answer: A. x = 10
To undo dividing by 2, multiply both sides by 2: x = 5 * 2 = 10.

12. In the expression 6x + 2y - 3, how many terms are there?

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Answer: B. 3
Terms are the parts of an expression separated by plus or minus signs; here they are 6x, 2y, and -3, which makes 3 terms.

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