Вопрос:

Ответ:

\[(2x + 3) + (3x + 4) + (5x + 5) =\]

\[= 12 - 7x\]

\[2x + 3 + 3x + 4 + 5x + 5 + 7x = 12\]

\[17x = 12 - 3 - 4 - 5\]

\[17x = 0\]

\[x = 0.\]