\[(7 - 5x) - (8 - 4x) + (5x + 6) = 8\]
\[7 - 5x - 8 + 4x + 5x + 6 = 8\]
\[4x + 5 = 8\]
\[4x = 8 - 5\]
\[4x = 3\]
\[x = \frac{3}{4}\]
\[x = 0,75.\]