\[\left( x^{2} - 4x + 1 \right)\left( x^{2} - 4x + 2 \right) = 2\]
\[Пусть\ \ t = x^{2} - 4x + 1:\]
\[t(t + 1) = 2\]
\[t^{2} + t - 2 = 0\]
\[t_{1} + t_{2} = - 1;\ \ t_{1} \cdot t_{2} = - 2\]
\[t_{1} = - 2,\ \ t_{2} = 1.\]