\[\boxed{\text{1137\ (1137).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[2a + 12 - (3 - a) \cdot 2 - a = 0\]
\[2a + 12 - 6 + 2a - a = 0\]
\[3a = - 6\]
\[a = - 2\]
\[Подставим:\]
\[y = - 2 \cdot 2 + 12 = 8\]
\[Ответ:y = 8.\ \]
\[\boxed{\text{1137.\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[1)\ 2x + 3y = 5\]
\[x = 1;\ \ y = 1 \Longrightarrow (1;1).\]
\[Ответ:(1;1).\]
\[2)\ x + 5y = 16\]
\[x = 11;\ \ y = 1 \Longrightarrow \ \ (11;1)\]
\[x = 6;\ \ y = 2 \Longrightarrow \ (6;2)\]
\[x = 1;\ \ y = 3\ \Longrightarrow (1;3)\]
\[Ответ:(11;1),\ (6;2),\ (1;3).\]