Question

甲、乙两人分别从A、B两地同时出发,相向而行,相遇时甲比乙多走12千米,相遇后甲再走4小时到B地,乙再走9小时到A地,求

Answer 1

x/v1=4 (1)

(x+12)/v2=9 (2)

(x+12)/[x/(x+12)v1]=9 (3)

(1)/(3)得

x^2/(x+12)^2=4/9 (4)

x/(x+12)=2/3

3x=2x+24

x=24

x+12=36

A、B两地距离:x+x+12=60km

甲v1=x/4=24/4=6km/h

乙v2=(x+12)/9=36/9=4km/h