Question

Let f(x) = 4x - 7 and g(x) = 2x - 3. Find (fog)(4).

Answer 1

`(f\circ g)(x)=4(2x-3)-7=8x-12-7=8x-19\\\\(f\circ g)(4)=8\cdot4-19=13`

Answer 2

13

Explanation:

(f∘g)(4) is another way of writing f(g(4)).

First, find g(4).

g(x) = 2x − 3

g(4) = 2(4) − 3

g(4) = 5

Now substitute into f(x).

f(x) = 4x − 7

f(g(4)) = 4g(4) − 7

f(g(4)) = 4(5) − 7

f(g(4)) = 13