\[\left\{ \begin{matrix}
x - y = - 2 \\
x - 2y = 4 \\
\end{matrix} \right.\ \text{\ \ \ \ \ }\]
\[\left\{ \begin{matrix}
x = y - 2\ \ \ \ \ \ \ \ \ \\
y - 2 - 2y = 4 \\
\end{matrix} \right.\ \text{\ \ \ \ \ \ }\]
\[\left\{ \begin{matrix}
x = y - 2 \\
- y = 6\ \ \ \ \\
\end{matrix} \right.\ \text{\ \ \ \ \ \ }\]
\[\left\{ \begin{matrix}
y = - 6 \\
x = - 8 \\
\end{matrix} \right.\ \]
\[Проверка:\ \]
\[\left\{ \begin{matrix}
- 8 - ( - 6) = - 2\ \ \\
- 8 - 2 \cdot ( - 6) = 4 \\
\end{matrix} \right.\ \text{\ \ \ \ \ }\]
\[\left\{ \begin{matrix}
- 2 = - 2 \\
4 = 4\ \ \ \ \ \ \\
\end{matrix} \right.\ \Longrightarrow верно.\]
\[Ответ:( - 8;\ - 6).\]