Решите методом подстановки систему уравнений: 3x+4y=-2, 6x-7y=11.

\[\left\{ \begin{matrix} 3x + 4y = - 2 \\ 6x - 7y = 11 \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ }\]

\[\left\{ \begin{matrix} x = \frac{- 2 - 4y}{3}\text{\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ } \\ 6 \cdot \left( \frac{- 2 - 4y}{3} \right) - 7y = 11 \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ }\]

\[\left\{ \begin{matrix} x = \frac{- 2 - 4y}{3}\text{\ \ \ \ \ \ \ \ \ \ \ \ } \\ - 4 - 8y - 7y = 11 \\ \end{matrix} \right.\ \]

\[\left\{ \begin{matrix} x = \frac{- 2 - 4y}{3} \\ - 15 = 15y\ \ \ \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ \ \ \ }\]

\[\left\{ \begin{matrix} y = - 1 \\ x = \frac{2}{3}\text{\ \ \ } \\ \end{matrix} \right.\ \]

\[Ответ:\left( \frac{2}{3}; - 1 \right)\text{.\ }\]