Решите систему уравнений: 8x+3y=31; 6x-5y=45.

\[\left\{ \begin{matrix} 8x + 3y = 31\ \ | \cdot 3 \\ 6x - 5y = 45\ \ | \cdot 4\ \\ \end{matrix} \right.\ \text{\ \ \ \ \ }\]

\[\left\{ \begin{matrix} 24x + 9y = 93\ \ \ \ \ \\ 24x - 20y = 180 \\ \end{matrix} \right.\ - \ \ \ \ \]

\[\left\{ \begin{matrix} 29y = - 87\ \ \\ x = \frac{45 + 5y}{6} \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ \ \ \ \ \ }\]

\[\left\{ \begin{matrix} y = - 3 \\ x = 5\ \ \ \\ \end{matrix} \right.\ \]

\[Ответ:(5;\ - 3).\]