Find the value of $x +y$ If $a=\frac{x}{x^2+y^2}$ and $b=\frac{y}{x^2+y^2}$ then find $x+y$
I find that $x+y/y=\frac{a+b}{b}$ but the ans in the form of a and B only.

$a^2+b^2={x^2\over{(x^2+y^2)^2}}+{y^2\over{(x^2+y^2)^2}}= {1\over{x^2+y^2}}$, $x=a(x^2+y^2), y=b(x^2+y^2)$ implies that $x+y={{a+b}\over{a^2+b^2}}$
