Happy new year to all :D

I 've just studying differential equations and I 've some equations need solve, please help me!

1. dy/dx = (x^2 - y^2) / 2xy

2. x * dy/dx -y = x^3

3. (x+ (e^-x)* siny)dx - (y+ (e^-x) cosx)dy = 0

And which method used to solve these type!

Thanks!(Happy)

Sorry, I don't know how to type math equations in this forum, could anyone show me(Wink)