化简得: 3(x+y)-4(x-y)=4
3x+3y-4x+4y=4
-x+7y=4
-x=4-7y
x=7y-4
(x+y/2)+(x-y/6)=1
2x+y/3=1
2(7y-4)+y/3=1
14y-8+y/3=1
42y-24+y=3
43y=27
y=27/43
x=7y-4=7×27/43-4=17/43