已知3/2=4/y=5/z不等于0,那么X+y+z/x-y+z=?

问题描述:

已知3/2=4/y=5/z不等于0,那么X+y+z/x-y+z=?

设x/3=y/4=z/5=t
x=3t y=4t z=5t
x+y+z/x-y+z=﹙3t+4t+5t﹚/﹙3t-4t+5t﹚=12t/4t=3