4x-3y-3z=x-3y+z=0
4x/z-3y/z-3=0.①
x/z-3y/z+1=0.②
①-②得：3x/z-4=0
x/z=4/3代入②得：4/3+1-3y/z=0
y/z=7/9
x:y=(4/3)/(7/9)=4:(7/3)=12:7
x:z=12:9
x:y:z=12:9:7
2)
(2x+3y-4z)/z=2x/z+3y/z-4
=8/3+7/3-4
=5-4
=1