Решите систему уравнений: 3-(x-2y)-4y=18; 2x-3y+3=2(3x-y).

\[\left\{ \begin{matrix} 3 - (x - 2y) - 4y = 18\ \ \\ 2x - 3y + 3 = 2(3x - y) \\ \end{matrix} \right.\ \]

\[\left\{ \begin{matrix} 3 - x + 2y - 4y = 18\ \ \\ 2x - 3y + 3 = 6x - 2y \\ \end{matrix} \right.\ \]

\[\left\{ \begin{matrix} x + 2y = - 15\text{\ \ \ \ \ \ \ } \\ 4x + y = 3\ \ \ \ \ \ | \cdot 2 \\ \end{matrix} \right.\ \]

\[\left\{ \begin{matrix} x + 2y = - 15 \\ 8x + 2y = 6\ \ \ \ \\ \end{matrix} \right.\ ( - )\]

\[- 7x = - 21\]

\[x = 3.\]

\[y = 3 - 4x = 3 - 12 = - 9.\]

\[Ответ:(3; - 9).\]