
\[\left\{ \begin{matrix}
9x - 30 - 10x + 10y = 3x + 4 \\
5x - 34 + 18y + 24 = 20y\ \ \ \ \ \ \\
\end{matrix} \right.\ \]
\[\left\{ \begin{matrix}
10y - 4x = 34\ \ \ \ \ \ \ \ \ \ \\
- 2y + 5x = 10\ \ | \cdot 5 \\
\end{matrix} \right.\ \text{\ \ \ \ \ }\]
\[\left\{ \begin{matrix}
10y - 4x = 34\ \ \ \ \ \\
- 10y + 25x = 50 \\
\end{matrix} + \right.\ \text{\ \ \ \ \ }\]
\[\left\{ \begin{matrix}
21x = 84\ \ \ \ \ \ \\
y = \frac{34 + 4x}{10} \\
\end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ \ \ \ }\]
\[\left\{ \begin{matrix}
x = 4 \\
y = 5 \\
\end{matrix} \right.\ \]
\[Ответ:(4;5).\]