# Problem 11

Algebra Level 5

$\frac{(z+z\sqrt{xy})^2}{(x+y)(z^2+1)}+\frac{2z}{(1+z^2)\sqrt{1+z^2}}$

Given that $$x,y,z$$ are positive reals and $$x(1-yz)=y+z$$. Find the maximum value of the expression above.