Answer
$\begin{bmatrix}
{50}&{-3}\\
{18}&{21}\end{bmatrix}$
Work Step by Step
In Problems 15 and 16, we found:
$ AC=\begin{bmatrix} {28}&{-9}\\{4}&{23}\end{bmatrix}$ and
$ BC=\begin{bmatrix} {22}&{6}\\{14}&{-2}\end{bmatrix} $
Now, calculate the sum
$AC+BC=\begin{bmatrix} {28}&{-9}\\{4}&{23}\end{bmatrix}+\begin{bmatrix} {22}&{6}\\{14}&{-2}\end{bmatrix} \\=\begin{bmatrix}
{28+22}&{-9+6}\\
{4+14}&{23+(-2)}\end{bmatrix} \\=\begin{bmatrix}
{50}&{-3}\\
{18}&{21}\end{bmatrix}$
