Question

Find (f∘g)(x).

f(x)=5x+1
g(x)=2x
Write your answer as a polynomial in simplest form.

Answer 1

(f o g)=f(g(x))
just sub
f(g(x))
sub g(x) for x in f(x)
g(x)=2x
2x=x in f(x)
f(g(x)=f(2x)=5(2x)+1=10x+1

(f o g)=10x+1