设x+y/5=y+z/6=z+x/7=m
x+y=5m,y+z=6m,z+x=7m
三式相加:2(x+y+z)=18m
x+y+z=9m
x=3m,y=2m,z=4m
x:y:z=3:2:4
2.设x=2m,y=7m,z=6m
4x-2y-z=-12m=-36
m=3
x=6,y=21,z=18
设x+y/5=y+z/6=z+x/7=m
x+y=5m,y+z=6m,z+x=7m
三式相加:2(x+y+z)=18m
x+y+z=9m
x=3m,y=2m,z=4m
x:y:z=3:2:4
2.设x=2m,y=7m,z=6m
4x-2y-z=-12m=-36
m=3
x=6,y=21,z=18