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

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

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

3x² = 36 then what is the value of x?

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

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

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

25.6% of 250 +√ ? = 119