if
f(x)=x^2+2x-4
and
g(x)=3x+1
find
f(g(x))=__x^2+__x+__

Step-by-step explanation:
f(x) = x² + 2x - 4
g(x) = 3x + 1
f(g(x)) = f(3x + 1)
f(3x + 1) = [3x + 1]² + 2[3x + 1] - 4
= 9x² + 6x + 1 + 6x + 2 - 4
= 9x² + 12x -1