how do i simplify this further

Question

x^2/sqrt(x^2+y^2)+y^2/sqrt(x^2+y^2)

Answer 1

Notice your common denominators. Add the numerators on top of that denominator

(x^2 + y^2)/sqrt(x^2 + y^2)

The next step should be obvious.
Any number divided by its square root equals the square root.