if f(x)=5x+2 and g(x)=3x-4,find (fog)(x)
5(3x-4)+2
15x-20+2
15x-18
Put g in f
so 5(3x-4)+2
15x-20+2
=15x-18
To find (fog)(x), you need to substitute g(x) into f(x).
First, let's find g(x):
g(x) = 3x - 4
Now, substitute g(x) into f(x):
f(g(x)) = 5(g(x)) + 2
Replace g(x) with its expression:
f(g(x)) = 5(3x - 4) + 2
Simplify:
f(g(x)) = 15x - 20 + 2
= 15x - 18
Therefore, (fog)(x) = 15x - 18.