\[\boxed{\text{589.}\text{\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]
Пояснение.
Решение.
\[x^{2} + 2x + q = 0;\ \ \ \ \]
\[\text{\ \ }x_{1}^{2} - x_{2}^{2} = 12\]
\[\left( - 2 - x_{2} \right)^{2} - x_{2}^{2} = 12\]
\[4 + 4x_{2} + x_{2}^{2} - x_{2}^{2} = 12\]
\[4x_{2} = 8\]
\[x_{2} = 2.\]
\[x_{1} = - 2 - 2 = - 4\]
\[q = x_{1}x_{2} = 2 \cdot ( - 4) = - 8.\]
\[Ответ:\ q = - 8.\ \]