\[x^{2} - 11x + q = 0;\ \ \ x_{1} = - 4.\]
\[\left\{ \begin{matrix} x_{1} + x_{2} = 11 \\ x_{1} \cdot x_{2} = q\ \ \ \ \\ \end{matrix} \right.\ \]
\[1)\ - 4 + x_{2} = 11\ \ \]
\[x_{2} = 15.\]
\[2)\ - 4 \cdot 15 = q\]
\[q = - 60.\]
\[Ответ:\ \ x_{2} = 15;\ \ q = - 60.\]