\[x^{2} + 7x = 18\]
\[x^{2} + 7x - 18 = 0\]
\[x_{1} + x_{2} = - 7;\ \ x_{1} \cdot x_{2} = - 18\]
\[x_{1} = - 9;\ \ x_{2} = 2.\]
\[Ответ:\ - 92.\]