\[30 + 5 \cdot (3x - 1) = 35x - 25\]
\[30 + 15x - 5 = 35x - 25\]
\[15x - 35x = - 25 - 25\]
\[- 20x = - 50\]
\[x = \frac{5}{2}\]
\[x = 2,5.\]