dy/dx= - F `_(x)(x;y)/F `_(y)(x;y)
F `_(x)(x;y)=(xe^y+ye^x–e^(xy))`_(x)=
=e^(y)*(x)`_(x)+y*(e^(x))`_(x)-e^(xy)*(xy)`_(x)=
=e^(y)+y*e^(x)-y*e^(xy)
F `_(y)(x;y)=(xe^y+ye^x–e^(xy))`_(y)=
=x*(e^(y))`_(y)+e^(x)*(y)`_(y)-e^(xy)*(xy)`_(y)=
=x*e^(y)+e^(x)-x*e^(xy)
dy/dx= - (e^(y)+y*e^(x)-y*e^(xy))/(x*e^(y)+e^(x)-x*e^(xy))