Algebra practice question

Answer: -14 or −14

Cross-multiply: 3(x + 4) = 2(x − 1), so 3x + 12 = 2x − 2. Subtract 2x: x + 12 = −2, so x = −14. Check: (−10)/2 = −5 and (−15)/3 = −5.

Common wrong answers

If you answered 5

5 is the common value of both sides at the solution, not x itself.

If you answered 14

14 has the wrong sign: x + 12 = −2 gives x = −14.

If you answered -10

−10 comes from 3x + 12 = 2x + 2, dropping the sign of the −1.

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