Answer
$-3F=\begin{bmatrix}
9 & -6
\\
15 & -3
\\
-6 & -12
\end{bmatrix}$
Work Step by Step
Multiplying each element of $F=
\begin{bmatrix}
-3 & 2
\\
-5 & 1
\\
2 & 4
\end{bmatrix}
$ by $-3,$ then
\begin{align*}
-3F&=
\begin{bmatrix}
-3(-3) & 2(-3)
\\
-5(-3) & 1(-3)
\\
2(-3) & 4(-3)
\end{bmatrix}
\\\\&=
\begin{bmatrix}
9 & -6
\\
15 & -3
\\
-6 & -12
\end{bmatrix}
.\end{align*}
Hence, $
-3F=\begin{bmatrix}
9 & -6
\\
15 & -3
\\
-6 & -12
\end{bmatrix}
.$