Advanced Math practice question

Answer: B. x = −2 and x = −4

Find two numbers that multiply to +8 and add to +6: those are −2 and −4, so (x + 2)(x + 4) = 0 and x = −2 or x = −4. The trap is choice A, taking the factors 2 and 4 as the roots without flipping their signs.

Why the other answers are wrong

A. x = 2 and x = 4

You found the factor pair 2 and 4 correctly but forgot to flip the signs — (x + 2)(x + 4) = 0 means x = −2 and x = −4.

C. x = −1 and x = −8

The numbers −1 and −8 multiply to +8 but add to −9, not the +6 the middle term requires; you need −2 and −4.

D. x = 1 and x = 8

1 and 8 multiply to 8, but they add to 9 rather than 6, and the roots of (x + 2)(x + 4) = 0 must be negative anyway.

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