Consider the differential equation. dxdy+yx(2(x2+y2)+1x2+y2−1)=0 It is solved as 2y(x2+y2)dy+ydy+x(x2+y2)dx−xdx=02y(x2+y2+2)dy−4ydy+ydy+x(x2+y2+2)dx−3xdx=02ydy+xdx=3(x2+y2+2xdx+ydy)2ydy+xdx=23(x2+y2+22xdx+2ydy) Integrate both sides, 2y2+x2=3log(x2+y2+2)+cx2+2y2−3logx2+y2+2=c