Решите уравнение: 12=(7x-9)-(11-x).

\[12 = (7x - 9) - (11 - x)\]

\[7x - 9 - 11 + x = 12\]

\[8x = 12 + 20\]

\[8x = 32\]

\[x = 32\ :8\]

\[x = 4.\]