\[\left\{ \begin{matrix}3x - 2y = 64\ \\3x + 7y = - 8 \\\end{matrix} \right.\ ( - )\]
\[- 9y = 72\]
\[y = - 8.\]
\[3x = 64 + 2y = 64 - 16 = 48\]
\[x = 48\ :3 = 16.\]
\[Ответ:(16; - 8).\]