\[31 + 25x + 2x^{2} = 7x - 9\]
\[2x^{2} + 18x + 40 = 0\ \ |\ :2\]
\[x^{2} + 9x + 20 = 0\]
\[x_{1} + x_{2} = - 9;\ \ x_{1} \cdot x_{2} = 20\]
\[x_{1} = - 5;\ \ x_{2} = - 4.\]
\[Ответ:\ - 5; - 4.\]