y/3-(x+1)/6=3①2(x-y/2)=3(x+y/18)②①2y-x-1=182y-x=19x=2y-19③②24/(2x-y)=18x+y(2x-y)*(18x+y)=24把③带入(3y-38)*(37y-342)=24
代入法算
y/3-(x+1)/6=3 2y-x-1=18x=2y-19 2(x-y/2)=3(x+y/18)12x-6y=18x+y6x=-7y x=-7 y=6