If $x = {2^{1/3}} - {2^{ - 1/3}},$ then $2{x^3} + 6x = $
$1$
$2$
$3$
None of these
The value of $\sqrt {[12\sqrt 5 + 2\sqrt {(55)} ]} $ is
Solution of the equation ${4.9^{x - 1}} = 3\sqrt {({2^{2x + 1}})} $ has the solution
The value of ${{15} \over {\sqrt {10} + \sqrt {20} + \sqrt {40} - \sqrt 5 - \sqrt {80} }}$ is
The square root of $\sqrt {(50)} + \sqrt {(48)} $ is
If $x = \sqrt 7 + \sqrt 3 $ and $xy = 4,$then ${x^4} + {y^4}=$