\[\boxed{\text{1283.\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]
\[x^{8} + x^{4} + 1 = \left( x^{8} + 2x^{4} + 1 \right) -\]
\[- x^{4} = \left( x^{4} + 1 \right)^{2} - x^{4} =\]
\[= \left( x^{4} + 1 - x^{2} \right)\left( x^{4} + 1 + x^{2} \right) =\]
\[= \left( \left( x^{2} + 1 \right)^{2} - 3x^{2} \right) \cdot\]
\[\cdot \left( \left( x^{2} + 1 \right)^{2} - x^{2} \right) =\]
\[= \left( x^{2} + 1 - \sqrt{3x} \right) \cdot\]
\[\cdot \left( x^{2} + 1 + \sqrt{3x} \right)\left( x^{2} + 1 - x \right) \cdot\]
\[\cdot (x^{2} + 1 + x)\]