$A = \left[ {\begin{array}{*{20}{c}}
2 \\
{ - 4}
\end{array}\,\,\,\,\begin{array}{*{20}{c}}
{ - 1} \\
3
\end{array}} \right]\,,\,X = \left[ {\begin{array}{*{20}{c}}
x \\
y
\end{array}} \right]\,,\,B = \left[ {\begin{array}{*{20}{c}}
4 \\
2
\end{array}} \right] \to X = {A^{ - 1}}B = \frac{1}{2}\left[ {\begin{array}{*{20}{c}}
3 \\
4
\end{array}\,\,\,\begin{array}{*{20}{c}}
1 \\
2
\end{array}} \right]\left[ {\begin{array}{*{20}{c}}
4 \\
2
\end{array}} \right] = \left[ {\begin{array}{*{20}{c}}
7 \\
{10}
\end{array}} \right]$