\[\left\{ \begin{matrix} 5x - 6y = 7\ \ \\ 10x + 6y = 8 \\ \end{matrix} \right.\ \ + \ \ \ \ \ \ \]
\[\left\{ \begin{matrix} 15x = 15\ \ \ \\ y = \frac{5x - 7}{6} \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ }\]
\[\left\{ \begin{matrix} x = 1\ \ \ \ \\ y = - \frac{1}{3} \\ \end{matrix} \right.\ \]
\[Ответ:\left( 1;\ - \frac{1}{3} \right).\]