Algebra practice question

Answer: 8

Multiply by 4: 3x − 4 = 20, so 3x = 24 and x = 8.

Common wrong answers

If you answered 3

3 comes from 3x − 4 = 5 (forgetting to multiply by 4).

If you answered 12

12 comes from 3x − 4 = 32, using 8 × 4 instead of 5 × 4.

If you answered 5.33

5.33 comes from 3x − 4 = 12; the right side is 5 × 4 = 20, not 12.

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