1/2(x+y)-1/3(x-y)=1 ①1/3(x+y)-1/4(x-y)=1 ②由①×6得 3(x+y)-2(x-y)=6，→x+5y=6 ③由②×12得 4(x+y)-3(x-y)=12，→x+7y=12 ④有④-③得 2y=6 y=3将y=3代入③得x+5×3=6，解得x=-9 所以方程组的解为x=-9 y=3
x=-9;y=3
x=-9,y=3
