\[x^{2} + \text{bx} + c = 0\]
\[- 8\ и\ 15\]
\[x_{1} + x_{2} = - 8 + 15 = 7 =\]
\[= - b \Longrightarrow b = - 7.\]
\[x_{1} \cdot x_{2} = \ - 8 \cdot 15 = - 120 =\]
\[= c \Longrightarrow c = - 120.\]
\[Ответ:b = - 7;\ \ c = - 120.\]