Answer
$\begin{bmatrix}
-\frac{11}{3} & -\frac{31}{3}\\
1 & \frac{3}{2}\\
-8 & -1\\
\end{bmatrix}$
Work Step by Step
First add the two matrices in the parentheses to create matrix X:
X = $\begin{bmatrix}
-5+7 & -1+5\\
3-9 & 4-1\\
0+6 & 13-1\\
\end{bmatrix}$
Then multiply matrix X by the scalar multiple $\frac{1}{6}$ to create matrix A:
A = $\begin{bmatrix}
2(\frac{1}{6}) & 4(\frac{1}{6})\\
-6(\frac{1}{6}) & 3(\frac{1}{6})\\
6(\frac{1}{6}) & 12(\frac{1}{6})\\
\end{bmatrix}$ = $\begin{bmatrix}
\frac{1}{3} & \frac{2}{3}\\
-1 & \frac{1}{2}\\
1 & 2\\
\end{bmatrix}$
Then multiply the matrix not in parentheses by the scalar multiple -1 to create matrix B:
B = $\begin{bmatrix}
4(-1) & 11(-1)\\
-2(-1) & -1(-1)\\
9(-1) & 3(-1)\\
\end{bmatrix}$ = $\begin{bmatrix}
-4 & -11\\
2 & 1\\
-9 & -3\\
\end{bmatrix}$
Then perform A + B to get the final answer:
$\begin{bmatrix}
-4+\frac{1}{3} & -11+\frac{2}{3}\\
2-1 & 1+\frac{1}{2}\\
-9+1 & -3+2\\
\end{bmatrix}$ = $\begin{bmatrix}
-\frac{11}{3} & -\frac{31}{3}\\
1 & \frac{3}{2}\\
-8 & -1\\
\end{bmatrix}$
