y/3-x+1/6=3,2(x-y/2)=3(x+y/18) 解这个方程组

y/3=3-1/6+x 2x-y=3x+y/6
y=9-0.5+3x -y=x+y/6
y=8.5+3x x=-7/6y
y=8.5+3(-7/6y) x=-7/6*9/17
y=8.5-3.5y x=-63/102
4.5y=8.5 x=-21/34
y=45/85
y=9/17