Question

Let f(x) = 5x - 7 and g(x) = x2 – 3x + 12.

(a) Find f(g(x)).

(b) Find g(f(x)).

Answer 1

(a) f(g(x)) = -5x + 53

(b) g(f(x)) = -5x + 19

Explanation:

I simplified x2 - 3x + 12 to -x + 12. Plug that into the x of f(x). f(x) = 5(-x +12) - 7 which equals -5x + 53. Same thing for g(f(x)). Plug in 5x - 7 in the x of g(x) which would be -(5x - 7) +12. You would get -5x + 19.