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