Answer
$X=\left[\begin{array}{ll}
4 & 7\\
7 & 4\\
2 & 2
\end{array}\right]$
Work Step by Step
$ 5(X-C)=D\qquad$... multiply both sides with $\displaystyle \frac{1}{5}$
$ X-C=\displaystyle \frac{1}{5}D\qquad$... add C to both sides
$X=\displaystyle \frac{1}{5}D+C$
$X=\displaystyle \frac{1}{5}\left[\begin{array}{ll}
10 & 20\\
30 & 20\\
10 & 0
\end{array}\right]+\displaystyle \left[\begin{array}{ll}
2 & 3\\
1 & 0\\
0 & 2
\end{array}\right]$
$=\left[\begin{array}{ll}
2 & 4\\
6 & 4\\
2 & 0
\end{array}\right]+\left[\begin{array}{ll}
2 & 3\\
1 & 0\\
0 & 2
\end{array}\right]$
$=\left[\begin{array}{ll}
4 & 7\\
7 & 4\\
2 & 2
\end{array}\right]$
