设x/2=y/3=z/4=kx=2k,y=3k,z=4k(2x+3y-z)/(x-2y+3z)=(4k+9k-4k)/(2k-6k+12k)=9/8
(9/8)
设x/2=y/3=z/4=k所以x=2k,y=3k,z=4k带入削去k即可结果为9/8