{3分之y减6分之x加1=3,2(x-2分之y)=3（x加18分之y y/3-(x+1/6)=3 2y-6x=19 (1) 2(x-y/2)=3(x+y/18) 2x-y=3x+y/6 12x-6y=18x+y 6x=7y (2) (1)+(2) 2y=19+7y y=-19/5 x=-133/30
