# nonlinear first order differential equation nonlinear

I was solving for the equation of a curve and I arrived at the following differential equation. However I do not know how to solve it:

$\frac{dy}{dx}=\frac{-x+\sqrt{x^2+y^2}}{y}$

$$ydy +xdx=dx \sqrt{x^2 +y^2} \to d (x^2+ y^2) =2 dx\sqrt{x^2+y^2}$$
Take $u=x^2+y^2$, then $du = 2\sqrt{u} dx$.