High School Pre-Cal

Question

Given f(x)=x²+x and g(x)=6-x, what is g(f(x))

 

A. x² -13x + 42

 

B. x² + 18x + 42

 

C. -x² - x + 6

 

D. -x^{2 + x + 6}

Answer 1

Answer C

 

take the expresiion (x² + x) and plug this in for x in the expression 6-x

 

6 - (x² + x)

 

6 - x² -x

 

-x² -x + 6