文字題:
2 Cars 280km apart setting out at the same time will meet in 4 hours
if they travel in opposite directons.
But they will be together in 14 hours
if they drive in the same direction.
Find their speed!
有冇高手知點solve~
Math - Simultaneous Equations
2010-12-28 2:37 am
回答 (1)
2010-12-28 2:53 am
✔ 最佳答案
Let the speeds of the cars be x km/h and y km/h, x>y.time X speed = distance
4(x+y)=280
14(x-y)=280
[(x+y) is the distance that 2 cars approaching each other per hour,
(x-y) is the distance that the faster car catch up the slower car per hour]
x+y=70......(1)
x-y=20.......(2)
[(1)+(2)]/2:
x=45
y=70-45=25
The speeds of the cars are 45km/h and 25km/h
收錄日期: 2021-04-15 16:51:29
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20101227000051KK01054