设1/(x+y)=u1/(x-y)=v解方程组10u+3v=-515u-2v=-1u=-0.2v=-1x+y=-5x-y=-1然后解得x=-3y=-2
令1/（x+y）=a,1/(x-y)=b10a+3b=-515a-2b=-1a=-1/5,b=-1x+y=-5,x-y=-1x=-3,y=-2
