Differential Equations: [xcsc(y/x)y]dx+xdy=0

2. (x csc y/x - y) dx + xdy=0
3. (x^2 + 2xy - 4y^2) dx - ( x^2 - 8xy - 4 y^2)=0
4. x^y ' = 4x^2 + 7xy + 2 y^2

Solution (2)
[xcsc(yx)y]dx+xdy=0

Let y = vx
dy = v dx + x dv

[xcsc(vxx)vx]dx+x(vdx+xdv)=0

(xcscvvx)dx+vxdx+x2dv=0

xcscvdx+x2dv=0

dxx+dvcscv=0

dxx+sinvdv=0

lnxcosv=c

lnxcos(yx)=c