Answer:
D.
Step-by-step explanation:
The distributive property is useful for this.
(f·g)(x) = f(x)·g(x)
= (x +4)·(3x² -7)
= x(3x² -7) +4(3x² -7)
= 3x³ -7x +12x² -28
Arranging the terms in standard form, we get ...
(f·g)(x) = 3x³ +12x² -7x -28 . . . . . . . matches choice D
