If $x = {2^{1/3}} - {2^{ - 1/3}},$ then $2{x^3} + 6x = $
$1$
$2$
$3$
None of these
If $x = 3 - \sqrt {5,} $ then ${{\sqrt x } \over {\sqrt 2 + \sqrt {(3x - 2)} }} = $
The square root of $\sqrt {(50)} + \sqrt {(48)} $ is
The rationalising factor of ${a^{1/3}} + {a^{ - 1/3}}$ is
If ${x^y} = {y^x},$then ${(x/y)^{(x/y)}} = {x^{(x/y) - k}},$ where $k = $
If ${a^{1/x}} = {b^{1/y}} = {c^{1/z}}$ and ${b^2} = ac$ then $x + z = $