Answer:
Choice 4.
Step-by-step explanation:
f(g(x))
Replace g(x) with x^2+8 since g(x)=x^2+8.
f(g(x))
f(x^2+8)
Replace old input,x, in f with new input, (x^2+8).
f(g(x))
f(x^2+8)
2(x^2+8)+5
Distribute:
f(g(x))
f(x^2+8)
2(x^2+8)+5
2x^2+16+5
Combine like terms:
f(g(x))
f(x^2+8)
2(x^2+8)+5
2x^2+16+5
2x^2+21
