## Intermediate Algebra (12th Edition)

We are given that $f(x)=x^{2}-9$, $g(x)=2x$, and $h(x)=x-3$. We are asked to find the value of $(g-h)(-3)$. We know that $(g-h)(x)=g(x)-h(x)$. Therefore, $(g-h)(-3)=(2(-3))-(-3-3)=(-6)-(-6)=-6+6=0$.