Answer
$\begin{bmatrix}
5 & 5\\
-1 & -2
\end{bmatrix}$
Work Step by Step
$\begin{bmatrix}
5 & -4\\
-2 & 6
\end{bmatrix}+\begin{bmatrix}
0 & 9\\
1 & -8
\end{bmatrix}=\begin{bmatrix}
5+0 & (-4)+9\\
(-2)+1 & 6+(-8)
\end{bmatrix}=\begin{bmatrix}
5 & 5\\
-1 & -2
\end{bmatrix}$
