\[\boxed{\mathbf{600\ (600).\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[\sqrt{x} = - x^{2}\]
\[\left\{ \begin{matrix} x = x^{4} \\ x \geq 0 \\ x \leq 0 \\ \end{matrix} \right.\ \]
\[x - x^{4} = 0\]
\[x\left( 1 - x^{3} \right) = 0\]
\[\left\{ \begin{matrix} x = 1 \\ x = 0 \\ x = 0 \\ \end{matrix} \right.\ \]
\[Ответ:x = 0.\]