Given X and Y matrices are square matrices of $2\times 2$
(i) $X+Y=\left[ \begin{matrix}
12+2 & 15+7 \\
11+4 & 17+9 \\
\end{matrix} \right]$
$=\left[ \begin{matrix}
14 & 22 \\
15 & 26 \\
\end{matrix} \right]$
(ii) $2X+3Y$
$2X=\left[ \begin{matrix}
14\times 2 & 22\times 2 \\
15\times 2 & 26\times 2 \\
\end{matrix} \right]$
$=\left[ \begin{matrix}
24 & 30 \\
22 & 34 \\
\end{matrix} \right]$
$3B=\left[ \begin{matrix}
2\times 3 & 7\times 3 \\
4\times 4 & 9\times 3 \\
\end{matrix} \right]$
$=\left[ \begin{matrix}
6 & 21 \\
12 & 27 \\
\end{matrix} \right]$
$2A+3B=\left[ \begin{matrix}
24+6 & 30+21 \\
22+12 & 34+27 \\
\end{matrix} \right]$
$=\left[ \begin{matrix}
30 & 51 \\
34 & 61 \\
\end{matrix} \right]$