Решите методом подстановки систему уравнений x+3y=13; 2x+y=6.

\[\left\{ \begin{matrix} x + 3y = 13 \\ 2x + y = 6\ \ \ \\ \end{matrix} \right.\ \Longrightarrow \left\{ \begin{matrix} y = 6 - 2x\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \\ x + 3 \cdot (6 - 2x) = 13 \\ \end{matrix} \right.\ \ \]

\[x + 18 - 6x = 13\]

\[- 5x = 13 - 18\]

\[- 5x = - 5\]

\[x = 1.\]

\[y = 6 - 2x = 6 - 2 \cdot 1 = 4.\]

\[\left\{ \begin{matrix} x = 1 \\ y = 4 \\ \end{matrix} \right.\ \]

\[Ответ:(1;4).\]