\[(x + 6)(x - 1) - (x + 3)(x - 4) = 5x\]
\[x^{2} + 6x - x - 6 - \left( x^{2} + 3x - 4x - 12 \right) - 5x = 0\]
\[x^{2} - 6 - x^{2} + x + 12 = 0\]
\[x + 6 = 0\]
\[x = - 6.\]
\[Ответ:x = - 6.\]