$\sqrt {(3 + \sqrt 5 )} $ is equal to
$\sqrt 5 + 1$
$\sqrt 3 + \sqrt 2 $
$(\sqrt 5 + 1)/\sqrt 2 $
${1 \over 2}(\sqrt 5 + 1)$
${4 \over {1 + \sqrt 2 - \sqrt 3 }} = $
The rationalising factor of ${a^{1/3}} + {a^{ - 1/3}}$ is
${{{{2.3}^{n + 1}} + {{7.3}^{n - 1}}} \over {{3^{n + 2}} - 2{{(1/3)}^{l - n}}}} = $
The value of $\sqrt {[12 - \sqrt {(68 + 48\sqrt 2 )} ]} = $
If ${a^x} = {b^y} = {(ab)^{xy}},$ then $x + y = $