\[\left\{ \begin{matrix} x - y = 3\ \ \ | \cdot 2 \\ 3x + 2y = 1\ \ \ \ \ \\ \end{matrix} \right.\ \text{\ \ \ \ \ }\]
\[\left\{ \begin{matrix} 2x - 2y = 6\ \ \ (1) \\ 3x + 2y = 1\ \ \ (2) \\ \end{matrix} \right.\ \]
\[(1) + (2) \Longrightarrow 5x = 7\]
\[\left\{ \begin{matrix} 5x = 7\ \ \ \ \ \\ x - y = 3 \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ }\]
\[\ \left\{ \begin{matrix} 5x = 7\ \ \ \ \ \ \\ y = x - 3 \\ \end{matrix} \right.\ \]