High School Pre-Cal

Question

Given f(x)=5x+2 and g(x)=x²+1, what is g(f(x))

 

A. 5x²+5

 

B. 5x²+7

 

C. 25x²+20x+4

 

D. 25x²+20x+5

 

 

Answer 1

f(x)=5x+2, g(x)=x²+1

g(f(x))=?

replace the x in g(x) with 5x+2

g(5x+2)=(5x+2)²+1

            =25x²+20x+4+1

            =25x²+20x+5 which is D.