$8787 \div 343 \times \sqrt{50} = ?$

$\left(2+\sqrt{2}+\frac{1}{2+\sqrt{2}}+\frac{1}{\sqrt{2}-2}\right) = ?$

If $a = \frac{\sqrt{5} + 1}{\sqrt{5} - 1}$ and $b = \frac{\sqrt{5} - 1}{\sqrt{5} + 1}$,then the value of $\frac{a^{2} + ab + b^{2}}{a^{2} - ab + b^{2}}$ is

If $\sqrt{\left(1+\frac{27}{169}\right)}=1+\frac{x}{13},$ then $x$ equals

The least perfect square,which is divisible by $21, 36$ and $66$ completely is

If $\frac{52}{x} = \sqrt{\frac{169}{289}}$,then the value of $x$ is