Answer
See below.
Work Step by Step
$2\begin{bmatrix}
1& -1 \\
0& -4 \\
3&2
\end{bmatrix}+\begin{bmatrix}
4& 6 \\
1& -3\\
-1&8
\end{bmatrix}=\begin{bmatrix}
2& -2 \\
0& -8 \\
6&4
\end{bmatrix}+\begin{bmatrix}
4& 6 \\
1& -3\\
-1&8
\end{bmatrix}=\begin{bmatrix}
2+4& -2+6 \\
0+1& -8-3 \\
6-1&4+8
\end{bmatrix}=\begin{bmatrix}
6& 4 \\
1& -11 \\
5&12
\end{bmatrix}$
