\[\left\{ \begin{matrix}
4y + 20 = 2 \cdot (3x - 4y) - 4 \\
16 - (5x + 2y) = 3x - 2y\ \ \ \\
\end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ }\]
\[\left\{ \begin{matrix}
4y + 20 = 6x - 8y - 4\ \ \\
16 - 5x - 2y = 3x - 2y \\
\end{matrix} \right.\ \]
\[\left\{ \begin{matrix}
6x - 12y = 24\ \ \ |\ :6 \\
8x = 16\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \\
\end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ }\left\{ \begin{matrix}
x = 2\ \ \ \ \ \ \ \ \ \ \ \\
x - 2y = 4 \\
\end{matrix} \right.\ \text{\ \ \ \ \ \ \ }\]
\[\left\{ \begin{matrix}
x = 2\ \ \ \ \ \ \ \ \ \ \ \ \\
2y = 2 - 4\ \\
\end{matrix} \right.\ \text{\ \ \ }\left\{ \begin{matrix}
x = 2\ \ \ \\
y = - 1 \\
\end{matrix} \right.\ \]
\[Ответ:(2;\ - 1).\]