已知:x⼀3=y⼀5=z⼀7,求代数式x+y+3z⼀3y-2z-x的值

2025-04-25 18:08:01
推荐回答(1个)
回答1:

设x/3=y/5=z/7=k
∴x=3k,y=5k,z=7k
∴(x+y+3z)/(3y-2z-x)
=(3k+5k+21k)/(15k-14k-3k)
=29k/(-2k)
=-29/2