Вопрос:

Ответ:

\[x^{2} + bx + c = 0\]

\[- 9\ \ и\ 12:\]

\[- b = - 9 + 12\ \ \]

\[- b = 3 \Longrightarrow b = - 3.\]

\[c = - 9 \cdot 12 \Longrightarrow c = - 108.\]

\[Ответ:b = - 3;c = - 108.\]