1. solve the problem first finding an integrating factor of susceptible form. y(x+y)dx+(xy+1)dy=0 2. Relevant equations form: M(x,y)dx+N(x,y)dy=0 intigrating factor: eint(1/n(dm/dy-dndx)dx 3. The attempt at a solution u(x)=eint(1/(xy+1)(y(x+y)d/dy-(xy+1)d/dx)dx this reduces to eint((x+y)/(xy+1))dx This is where I need help. my integration is not good. I know that if I can solve for the integrating factor then I can solve for the equation because it will be in exact form. Thanks for any help.