Answer:
(f*g)(x) = 3x³+12x²-7x-28
Step-by-step explanation:
What (f*g)(x) means is that we multiply f(x) by g(x):
f(x) = x+4
g(x) = 3x²-7
(f*g)(x) = f(x)*g(x) = (x+4)(3x²-7) = (x)(3x²)+(x)(-7)+(4)(3x²)+(4)(-7) = 3x³-7x+12x²-28 = 3x³+12x²-7x-28