\[(3x - 5)^{2} - 5 \cdot (5 + 3x) = 0\]
\[9x^{2} - 30x + 25 - 25 - 15x = 0\]
\[9x^{2} - 45x = 0\]
\[9x(x - 5) = 0\]
\[x = 0\ \ \ \ \ \ \ \ \ \ \ x - 5 = 0\]
\[\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ x = 5\]
\[Ответ:x = 0;\ \ x = 5.\]