Advanced Math practice question

Answer: A. 16x

Expand both: (x + 4)² = x² + 8x + 16 and (x − 4)² = x² − 8x + 16. Subtracting, the x² and the 16 cancel and the middle terms combine: 8x − (−8x) = 16x.

Why the other answers are wrong

B. 0

The two squares are not equal — (x + 4)² and (x − 4)² differ in their middle terms, +8x and −8x. Their difference is 16x, not zero.

C. 32

32 would come from adding the constants 16 + 16, but the constants cancel in a subtraction; it's the x terms that survive.

D. 2x² + 32

2x² + 32 is what you get by ADDING the two squares (and dropping the middle terms). This is a subtraction.

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