{(x^2-(y^2)[e^(x/y)]}dx+(x^2+xy)[e^(x/y)]dy=0
更新1:
I am so sorry that my messy typing make you missunderstand the question... In the question, the part next to the dx should be x^2 - (y^2)[e^(x/y)] but not ( x^2 - y^2 ) [e^(x/y)] I hope you can help me again~~