Answer
$\begin{bmatrix}
9 & 15
\\
6 & 24
\end{bmatrix}$
Work Step by Step
Adding the corresponding elements of the matrices, the given matrix expression, $
\begin{bmatrix}
3 & 5
\\
2 & 8
\end{bmatrix}
+
\begin{bmatrix}
3 & 5
\\
2 & 8
\end{bmatrix}
+
\begin{bmatrix}
3 & 5
\\
2 & 8
\end{bmatrix}
,$ simplifies to
\begin{align*}
&
\begin{bmatrix}
3+3+3 & 5+5+5
\\
2+2+2 & 8+8+8
\end{bmatrix}
\\\\&=
\begin{bmatrix}
9 & 15
\\
6 & 24
\end{bmatrix}
.\end{align*}