3x² = 36 then what is the value of x?

If $${{k^2}\over {k^2-2k+1}}={1\over 6}$$, then what is the value of $${1\over k^3}+k3$$ ?

If $$ a={{\sqrt{3}+\sqrt{2}}\over {\sqrt{3}-\sqrt{2}}}$$ and $$ b={{\sqrt{3}-\sqrt{2}}\over {\sqrt{3}+\sqrt{2}}}$$, then find the value  of $$ {a^2\over b}+{b^2\over a}=?$$

On simplification of   $$ {(2.664)^2-(2.356)^2\over0.288}$$

The smallest number that must be subtracted from 1000 to make the resulting number a perfect square is 

Simplify  $$ ^{3}\sqrt{-2197} × ^{3}\sqrt{{-125}} \ ÷ ^{3}\sqrt{27\over512}$$.

If  $$\sqrt{2}=1.414$$, the value of $${ \sqrt{2}-1\over\sqrt{2}+1}$$  is nearest to 

The value of x in the given equation
$$ {23 ^2 + \sqrt{x}=625}$$