Решите систему уравнений удобным для вас способом: 12+3y-9=2x+10; 8x+20=10+2(3x+2y).

\[\left\{ \begin{matrix} 12 + 3y - 9 = 2x + 10\ \ \ \ \ \ \ \ \ \\ 8x + 20 = 10 + 2(3x + 2y) \\ \end{matrix} \right.\ \]

\[\left\{ \begin{matrix} 3y - 2x = 7\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \\ 8x + 20 = 10 + 6x + 4y \\ \end{matrix} \right.\ \]

\[\left\{ \begin{matrix} 3y - 2x = 7\ \ \ \ \ \ \ \ \ \ \ \\ - 4y + 2x = - 10\ \\ \end{matrix} \right.\ ( + )\]

\[- y = - 3\]

\[y = 3.\]

\[2x = 3y - 7 = 9 - 7 = 2\]

\[x = 1.\]

\[Ответ:(1;3).\]