If 12x – 15 y =9x + 5y, the value of $$ {x^{2}+{y^{2}}\over{x^{2}-y^{2}}}$$ is

The value of $${\sqrt{40+\sqrt{9\sqrt{81}}} }$$ is

The sum of the squares of two positive integers is 100 and the difference of their squares is 28. The sum of the numbers is: 

If $${4x^2={15^2-9^2}}$$ then the value of x is

(0.04)^-1.5 on simplification gives: 

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

45% of 224×?% of 120=8104.32

If 3x + 7y=75, 5x- 5y= 25, then the value of (x +y)=?

The value of   $$ {(0.03)^2 - (0.01)^2}\over 0.03-0.01 $$