\[\boxed{\text{585.}\text{\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]
Пояснение.
Решение.
\[5x^{2} + bx + 24 = 0\ \ \ \ \ \ |\ :5\ \ \ \ \ \ \ \ \ \ \ \ \ \ \]
\[x^{2} + \frac{b}{5}x + \frac{24}{5} = 0\]
\[x^{2} + 0,2bx + 4,8 = 0;\ \ \ \ \ x_{1} = 8:\]
\[- 0,2b = 8 + 0,6 = 8,6\]
\[b = - \frac{8,6}{0,2} = - \frac{86}{2} = - 43.\]
\[Ответ:b = - 43;x_{2} = 0,6.\]