｛x+ y)／2-(x-y)／3＝2，①4（x +y）－5（x-y）＝2。②①*15-②，得7(x+y)/2=28,x+y=8,③代入②，32-5(x-y)=2,30=5(x-y),x-y=6.④(③+④)/2,得x=7,代入③，得y=1.
