Simplify the following expression.

 25-(4÷2)+11.5+9.5

Simplify the following equation.
$$ {(100)}^{1\over2}.{(0.001)}^{1\over3}-{(0.0016)}^{1\over4}.{3}^{0}+({5\over4})^{-1} $$

Given that ( 1² +2²+3²+………..+10²)=385, the value of (2²+4²+6²+……20²) is equal to

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

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

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

What is the value of $$ {0.55 × 4.5\over 0.81}$$ ?

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

If $${a+b=10}$$ and $$ \sqrt{a\over b}-13=-\sqrt{b\over a}-11$$, then what is the value of $${3ab+4a^2+5b^2}$$?