Algebra practice question

Answer: A. −4

Subtract 7 from both sides: −2x = 8. Divide by −2: x = −4. Check: 7 − 2(−4) = 7 + 8 = 15.

Why the other answers are wrong

B. 4

4 drops the sign. Dividing 8 by −2 gives −4, not 4. Check: 7 − 2(4) = −1, not 15.

C. 11

11 comes from adding 7 to 15 instead of subtracting it: (15 + 7)/2. The 7 is on the same side as −2x, so it comes off: 15 − 7 = 8.

D. −11

−11 adds the 7 AND keeps a sign error. Start with 7 − 2x = 15, subtract 7, then divide by −2.

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