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

The value of   $${(75.8)^2-(55.8)^2\over20}$$

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 $$ {a^2\over b}+{b^2\over a}=?$$

Simplify the following expression.

 25-(4÷2)+11.5+9.5

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

Direction: what should come in place at question mark(?).

$$ {\sqrt{4489}+(71)^{2}-(?)^{2}=2707}$$

If the sum of the squares of three consecutive natural numbers is 110, then the smallest of these natural numbers is:

If $$ {y={2x-1\over x+3}}$$ find x when y=1