Advanced Math practice question

Answer: A. 3x − 2

3x² + 10x − 8 = (3x − 2)(x + 4): check 3x·x = 3x², the outer and inner terms 12x − 2x = 10x, and (−2)(4) = −8.

Why the other answers are wrong

B. 3x + 2

(3x + 2)(x − 4) = 3x² − 10x − 8, the wrong sign on the middle term.

C. x − 4

(x − 4)(3x + 2) gives −10x, not +10x.

D. 3x − 4

(3x − 4)(x + 2) = 3x² + 2x − 8.

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