\[\left\{ \begin{matrix} x - 3y = 4 \\ 2x - y = 3 \\ \end{matrix} \right.\ \text{\ \ \ \ \ }\]
\[\left\{ \begin{matrix} x = 4 + 3y\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \\ 2 \cdot (4 + 3y) - y = 3 \\ \end{matrix} \right.\ \text{\ \ \ \ }\]
\[\left\{ \begin{matrix} x = 4 + 3y\ \ \ \ \ \ \ \ \\ 8 + 6y - y = 3 \\ \end{matrix} \right.\ \text{\ \ \ \ }\]
\[\left\{ \begin{matrix} x = 4 + 3y \\ 5y = - 5\ \ \ \ \ \\ \end{matrix} \right.\ \]
\[\left\{ \begin{matrix} y = - 1 \\ x = 1\ \ \ \\ \end{matrix} \right.\ \]
\[Ответ:(1;\ - 1).\]