${{{{2.3}^{n + 1}} + {{7.3}^{n - 1}}} \over {{3^{n + 2}} - 2{{(1/3)}^{l - n}}}} = $
$1$
$3$
$-1$
$0$
Let ${7 \over {{2^{1/2}} + {2^{1/4}} + 1}}$$ = A + B{.2^{1/4}} + C{.2^{1/2}} + D{.2^{3/4}}$, then $A+B+C+D= . . .$
The value of $\sqrt {[12\sqrt 5 + 2\sqrt {(55)} ]} $ is
The rationalising factor of ${a^{1/3}} + {a^{ - 1/3}}$ is
The rationalising factor of $2\sqrt 3 - \sqrt 7 $ is
$\root 4 \of {(17 + 12\sqrt 2 )} = $