某工程队挖一条水渠,挖了全长的1/5,离中点还有270米,这条水渠全长是多少米?

问题描述:

某工程队挖一条水渠,挖了全长的1/5,离中点还有270米,这条水渠全长是多少米?

设全长为x米.
1/5x = 1/2x - 270
3/10x = 270
x = 270 ÷ 3/10
x = 900
答:这条水渠全长900米.
一楼的也对.