（x+y）/2+(x-y)/3=6 ①4(x+y)-5(x-y)=2 ②①*8得4(x+y)+8/3(x-y)=48 ③③-②得（8/3+5）(x-y)=46解得 x-y=6 ④把x-y=6带入②解得 x+y=8 ⑤④与⑤联立方程组解得 x=7y=1
x=7，y=1
