\[\left( x^{2} - x + 1 \right)\left( x^{2} - x - 2 \right) = 378\]
\[Пусть\ t = x^{2} - x + 1:\]
\[t(t - 3) = 378\]
\[t^{2} - 3t - 378 = 0\]
\[t_{1} + t_{2} = 3;\ \ \ t_{1} \cdot t_{2} = - 378\]
\[t_{1} = 21;\ \ \ \ t_{2} = - 18.\]
\[Подставим:\]
\[1)\ x^{2} - x + 1 = 21\]
\[x^{2} - x - 20 = 0\]
\[D = 1 + 80 = 81\]
\[x_{1} = \frac{1 - 9}{2} = - 4;\ \ \ x_{2} = \frac{1 + 9}{2} = 5.\]
\[2)\ x^{2} - x + 1 = - 18\]
\[x^{2} - x + 19 = 0\]
\[D = 1 - 76 = - 75 < 0\]
\[нет\ корней.\]
\[Ответ:x = - 4;\ \ x = 5.\]