x+y/2=2y-z/3=2
*6后=3x+3y=4y-2z=12
得x+y=4①
2y-z=6②
①-②=x-y+z=-2③
x-3y+z=10 ④
④-③=-2y=12
y=-6
代入x+y/2=2得x=10
代入2y-z/3=2得z=-18