10/(x+y) + 3/(x-y) = -5.(1)
15/(x+y) - 2/(x-y) = -1.(2)
(1)×3 - (2)×2得：
(9+4)/(x-y)=-13
x-y=-1.(4)
(1)×2 + (2)×3得：
(20+45)/(x+y)=-13
x+y=-5.(5)
(4)+(5)得：
2x=-6
x=-3
代回（4）得：
y=x+1=-2