\[x^{3} - 64x = 0\]
\[x\left( x^{2} - 64 \right) = 0\]
\[x = 0\ \ \ \ \ \ \ \ \ \ \ x^{2} = 64\]
\[\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ x = \pm 8\]
\[Ответ:\ \ x = 0;\ \ x = \pm 8.\]