Multiply $\sqrt{21\cdot -1}\sqrt{2}$

$\left(\sqrt{2}\sqrt{13+\sqrt{7}}-2\sqrt{5-\sqrt{7}}\right)\cdot\frac{1}{\sqrt{3-\sqrt{7}}}$

$\left(\frac{2}{3}+\frac{2}{5}\right)\left(\frac{3}{6}+\frac{3}{1}\right)$

$6\frac{1}{2}\cdot \left(2+1\right)$

$9^{\frac{1}{3}}\left(\sqrt{2}+1\right)^{\frac{1}{3}}\left(27-2\sqrt{162}\right)^{\frac{1}{6}}$

$\frac{5}{24}\cdot \left(41^{\frac{3}{2}}-5^3\right)$

$\frac{2}{\sqrt{5}+\sqrt{3}}\cdot \frac{\sqrt{+5}-\sqrt{3}}{\sqrt{5}-\sqrt{3}}$

$\log\left(5\right)\cdot \frac{625}{25^{\frac{1}{3}}}$