Решите методом сложения систему уравнений 4x-7y=1; 2x+7y=11.

\[\left\{ \begin{matrix} 4x - 7y = 1\ \ \ \\ 2x + 7y = 11 \\ \end{matrix} \right.\ ( + )\]

\[6x = 12\]

\[x = 2.\]

\[\left\{ \begin{matrix} 7y = 4x - 1 \\ x = 2\ \ \ \ \ \ \ \ \ \ \ \ \\ \end{matrix} \right.\ \Longrightarrow \left\{ \begin{matrix} 7y = 4 \cdot 2 - 1 \\ x = 2\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \\ \end{matrix} \right.\ \]

\[\left\{ \begin{matrix} x = 2\ \ \ \\ 7y = 7 \\ \end{matrix} \right.\ \Longrightarrow \left\{ \begin{matrix} x = 2 \\ y = 1 \\ \end{matrix} \right.\ \]

\[Ответ:(2;1).\]