求dy/dx...什么公式都用不上

y-e^(-xy)=x-e^(xy)dy/dx-e^(-xy)*(-y-x*dy/dx)=1-e^(xy) *(y+x*dy/dx)dy/dx+e^(-xy)*(y+x*dy/dx)=1-e^(xy) *(y+x*dy/dx)(1+xe^(-xy)+xe^(xy))*dy/dx=1-ye^(xy)-ye^(-xy)dy/dx=[1-ye^(xy)-ye^(-xy)]/(1+xe^(-xy)+xe^...