Answer
$15$.
Work Step by Step
The given functions are
$f(x)=3x$ and $g(x)=2x-3$.
Plug $x=-1$ into the given functions.
$f(-1)=3(-1)$ and $g(-1)=2(-1)-3$
Simplify.
$f(-1)=-3$ and $g(-1)=-5$
Use $(fg)(-1)=f(-1)\cdot g(-1)$.
Substitute both functions.
$(fg)(-1)=(-3)\cdot (-5)$
Simplify.
$(fg)(-1)=15$.
