用一根绳子测量井深,直接量,井外余5米.对折量,离井口还差4米.井深几米?绳子长几米?

用一根绳子测量井深,直接量,井外余5米.对折量,离井口还差4米.井深几米?绳子长几米?
用一根绳子测量井深,直接量,井外余5米.对折量,离井口还差4米.井深几米?绳子长几米?

用一根绳子测量井深,直接量,井外余5米.对折量,离井口还差4米.井深几米?绳子长几米?
设绳子长x米.


x-5=2分之x+4
x-2分之x=5+4
2分之x=9
x=18


井深=18-5=13米


你的采纳是我回答的动力!

x/2+4=x-5
x+8=2x-10
x=18
18-5=13
绳长18m，井深13m