\[\boxed{\mathbf{99}.}\]
\[1)\ x\sqrt{2} = \sqrt{2x^{2}};\ \ x > 0\]
\[2)\ x\sqrt{2} = - \sqrt{2x^{2}};\ \ x < 0\]
\[3) - a\sqrt{3} = \sqrt{3a^{2}};\ \ a \leq 0\]
\[4) - a\sqrt{3} = - \sqrt{3a^{2}};\ \ a \geq 0\]
\[5)\ a^{2}b\sqrt{b} = \sqrt{a^{4}b^{3}};\ \ a < 0;\]
\[\ \ b > 0\]
\[6)\ a^{3}b\sqrt{- b} = \sqrt{- a^{6}b^{3}};\ \ a < 0;\ \ \]
\[b \leq 0.\]