已知x/3=y/4=z/5≠0,求分式(x+y-z)/(x-y+z)的值

Question

已知x/3=y/4=z/5≠0,求分式(x+y-z)/(x-y+z)的值

Answer 1

设x/3=y/4=z/5=k
所以
x=3k
y=4k
z=5k
所以
(x+y-z)/(x-y+z)
=（3k+4k-5k）/(3k-4k+5k)
=2k/4k
=1/2