\(\left[\begin{array}{ccc}2x - y\\3x + 4y\end{array}\right] = \left[\begin{array}{ccc}7\\-6\end{array}\right]\)
\(\left[\begin{array}{ccc}2&-1\\3&4\end{array}\right]\left[\begin{array}{ccc}x\\y\end{array}\right] = \left[\begin{array}{ccc}7\\-6\end{array}\right]\)
\(\left[\begin{array}{ccc}x\\y\end{array}\right] = \frac{1}{11}\left[\begin{array}{ccc}4&1\\-3&2\end{array}\right]\left[\begin{array}{ccc}7\\-6\end{array}\right] = \frac{1}{11}\left[\begin{array}{ccc}22\\-33\end{array}\right] = \left[\begin{array}{ccc}2\\-3\end{array}\right]\)
\((x, y) = (2, -3)\)
