Question

Find (f∘g)(x).

f(x)=2x
g(x)=x+4
Write your answer as a polynomial in simplest form.

Answer 1

(f∘g)(x) = 2x + 12

Explanation:

(f∘g)(x) =

f(g(x)) =

2(g(x)) + 4 = ==> substitute g(x) for x in f(x) = 2x + 4

2(x + 4) + 4 = ==> substitute x + 4 for g(x)

2x + 2*4 + 4 = ==> use distribution property on x and 4

2x + 8 + 4 = ==> simplify

(f∘g)(x) = 2x + 12