I just need a refresher I guess. I'm getting caught up with how to balance an equation with a variable exponent.

This isn't homework, I'm studying for the CLEP exams, and am not asking for the answer, just a step by step aproach to how to solve this.

f(x)=4x^2+5

g(x)=2^x

f(g(-1))=n

Solve for n

I start by deviding both the first equations by (x) ending up with

f=4x+5

g=(2^x)/x

Can this be simplified any further? Is my math correct? How would I solve for x?