Answer
$(f-g)(x)=x^2+2x-13$
$(f-g)(5)=22$.
Work Step by Step
The difference $f-g$ of two functions $f$ and $g$ is obtained by subtracting the expressions of the two functions:
$(f-g)(x)=f(x)-g(x)$
Substitute $f(x)=x^2+3x-15$ and $g(x)=x-2$:
$(f-g)(x)=x^2+3x-15-(x-2)$
Simplify.
$(f-g)(x)=x^2+3x-15-x+2$
$(f-g)(x)=x^2+2x-13$
Plug $x=5$.
$(f-g)(5)=5^2+2(5)-13$
Simplify.
$(f-g)(5)=25+10-13$
$(f-g)(5)=35-13$
$(f-g)(5)=22$.
