Решите систему уравнений 5x-2y=11; 4x-y=4.

Ответ:

\[\left\{ \begin{matrix} 5x - 2y = 11\ \ \ \ \ \ \ \ \ \ \ \ \\ 4x - y = 4\ \ \ | \cdot ( - 2) \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ }\]

\[\left\{ \begin{matrix} 5x - 2y = 11\ \ \ \ \ \ \ (1) \\ - 8x + 2y = - 8\ \ \ (2) \\ \end{matrix} \right.\ \]

\[(1) + (2) \Longrightarrow - 3x = 3 \Longrightarrow x = - 1.\]

\[\left\{ \begin{matrix} x = - 1\ \ \ \ \ \ \\ y = 4x - 4 \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ \ }\left\{ \begin{matrix} x = - 1\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \\ y = 4 \cdot ( - 1) - 4 \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ }\]

\[\left\{ \begin{matrix} x = - 1 \\ y = - 8 \\ \end{matrix} \right.\ \]

\[Ответ:( - 1;\ - 8).\]