Answer
$x^{3}-3x^{2}-9x+27$
Work Step by Step
We are given that $f(x)=x^{2}-9$, $g(x)=2x$, and $h(x)=x-3$.
We know that $(fh)(x)=f(x)\times h(x)$.
Therefore, $(fg)(x)=(x^{2}-9)\times(x-3)$.
We can use the FOIL method to further simplify this function.
First terms: $x^{2}\times x=x^{2+1}=x^{3}$
Outer terms: $x^{2}\times-3=-3x^{2}$
Inner terms: $-9\times x=-9x$
Last terms: $-9\times-3$
Add together: $x^{3}+(-3x^{2})+(-9x)+27=x^{3}-3x^{2}-9x+27$
