Let ${7 \over {{2^{1/2}} + {2^{1/4}} + 1}}$$ = A + B{.2^{1/4}} + C{.2^{1/2}} + D{.2^{3/4}}$, then $A+B+C+D= . . .$
$A = 1$
$B = -3$
$C = 2$
All of these
The number of integers $q , 1 \leq q \leq 2021$, such that $\sqrt{ q }$ is rational, and $\frac{1}{ q }$ has a terminating decimal expansion, is
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If ${a^x} = {b^y} = {(ab)^{xy}},$ then $x + y = $
The rationalising factor of ${a^{1/3}} + {a^{ - 1/3}}$ is
The greatest number among $\root 3 \of 9 ,\root 4 \of {11} ,\root 6 \of {17} $ is