\[\ \ x² = 46\]
\[x = \pm \sqrt{46}\]
\[Ответ:x = \pm \sqrt{46}.\]
\[\ b \leq 0:\]
\[\frac{1}{3}b³\sqrt{9b^{2}} = \frac{1}{3} \cdot 3b³|b| = - b^{4}.\]