dy/dx=(xy+3x-y-3)/(xy-2x+4y-8)=(x-1)(y+3)/(x+4)(y-2)然后呢？(y-2)dy/(y+3)=(x-1)dx/(x+4)已经是变量分离方程，两边积分可求解(y+3-5)dy/(y+3)=(x+4-5)dx/(x+4)积分得通y-ln|y+3|=x-5ln|x+4|+C