\[\boxed{\text{682\ (682).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[b \cdot ( - 2b) = - 2b\]
\[- 2b^{2} + 2b = 0\]
\[- 2b(b - 1) = 0\]
\[b_{1} = 0\ \ \ \ \ \ \ b_{2} = 1\]
\[c_{1} = - 2 \cdot 0 = 0\ \ (c \neq 0)\]
\[c_{2} = - 2 \cdot 1 = - 2.\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \]
\[Ответ:b = 1,\ c = - 2\text{.\ }\]