Algebra practice question

Answer: C. 7

Distribute: 5x − 10 = 3x + 4. Subtract 3x: 2x − 10 = 4. Add 10: 2x = 14, so x = 7. Distribute before you collect terms.

Why the other answers are wrong

A. 5

Check it: 5(5 − 2) = 15 but 3(5) + 4 = 19, so these aren't equal. Distribute first to get 5x − 10 = 3x + 4, then solve.

B. 6

Substituting gives 5(6 − 2) = 20 versus 3(6) + 4 = 22 — not equal. After distributing, 2x − 10 = 4 leads to 2x = 14.

D. 8

Substituting gives 5(8 − 2) = 30 versus 3(8) + 4 = 28 — not equal. From 2x = 14, dividing by 2 gives x = 7.

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