(x+y)/2-(x-y)/3=5/6 ①(x+y)/6-(x-y)/3=1/2 ②解：①②等号两边分别同时乘以6去分母得：3(x+y)-2(x-y)=5 (x+y)-2(x-y)=3 令(x+y)=a,(x-y)=b得：3a-2b=5 (3)a-2b=3 (4)(3)-(4)得：2a=2,a=1代入(4)解得：b=-1那么，x+y=1 x-y=-1解得：x=0,y=1
