y/3-(x+1)/6=3 两边乘以6 得 2y-(x+1)=18x-2y+19=0 两边乘以66x-12y+19*6=0(1)2(x-y/2)=3(x+y/18) 化简得 2x-y=3x+y/6 两边乘以6 得12x-6y=18x+y 6x+7y=0 (2) (1)-(2)-19y+19*6=0y=6带回(2)6x+7*6=0x=-7
