\[x^{3} - 2x = 0\]
\[x\left( x^{2} - 2 \right) = 0\]
\[x\left( x - \sqrt{2} \right)\left( x + \sqrt{2} \right) = 0\]
\[x = 0;\ \ x = \sqrt{2};\ \ x = - \sqrt{2}.\]
\[Ответ:x = \pm \sqrt{2};\ \ x = 0.\]