1.(x+2y)dx-(y-1)dy=0

y=-1

x=-2

w=x+2

z=y+1

u=z/w

(w+2uw)dw-(uw)(udw+wdu)

w(1+2u)dw-w(u)(udw+wdu)

(1+2u)dw- (u^2dw+uwdu)

(1+2u-u^2)dw- (uw)du

dw/w- (u)/(1+2u-u^2)du

ln|w|- and here I get a really odd result when I integrate.

What am I doing wrong?

2.

(3x-2y+4)dx-(2x+7y-1)dy=0