有甲乙丙三根绳子甲长5.5米比乙长2.4米比丙短1.39米乙和丙共长多少米?

有甲乙丙三根绳子甲长5.5米比乙长2.4米比丙短1.39米乙和丙共长多少米?
有甲乙丙三根绳子甲长5.5米比乙长2.4米比丙短1.39米乙和丙共长多少米?

有甲乙丙三根绳子甲长5.5米比乙长2.4米比丙短1.39米乙和丙共长多少米?
设y,z
甲=y+2.4=z-1.39=5.5
y=3.1 z=6.89 y+z=9.99
答案9.99米