Answer:
4x^3+x^2-20x-5
Step-by-step explanation:
f(x)=4x+1 and g(x)=x^2-5
(fg)(x) = f(x) *g(x)
= (4x+1) *(x^2-5)
FOILing
First 4x*x^2 = 4x^3
outer 4x*-5 = -20x
inner 1 * x^2 = x^2
last 1 * -5 = -5
Add them together
= 4x^3 -20x+x^2-5
Put the terms in order from greatest power to least power
=4x^3+x^2-20x-5
