city A is 100km to the west of city B. David rides a bicycle 15km/h from city A to the west. At the same time, Alice drives a car Y km/h from city B to the west.
a)Express in terms of Y, the distance between David and Alice after 2 hours.
b)If Alice catches up with David after 2.5 hours , find the value of Y.
請列明步驟！thx@@@
f.1 maths question~plz help..............((fast......))
2006-10-27 1:33 am
回答 (3)
2006-10-27 1:38 am
✔ 最佳答案
a)the distance between David and Alice after 2 hours
= 100 - 2Y + 2 x 15
= 100 - 2Y + 30
= 130 - 2Y
b)
100 + 15 x 2.5 = 2.5Y
137.5 = 2.5Y
Y = 55
2006-10-27 1:53 am
a)100 - 2Y + 2 x 15
= 100 - 2Y + 30
= 130 - 2Y
b)100 + 15 x 2.5 = 2.5Y
137.5 = 2.5Y
Y = 55
= 100 - 2Y + 30
= 130 - 2Y
b)100 + 15 x 2.5 = 2.5Y
137.5 = 2.5Y
Y = 55
2006-10-27 1:39 am
a) Distance between David & Alice is
= (15 X 2 + 100 ) - Y X 2
b) 0 = (15 X 2.5 + 100) - Y X 2.5
2.5Y = 137.5
Y= 55 km/h
= (15 X 2 + 100 ) - Y X 2
b) 0 = (15 X 2.5 + 100) - Y X 2.5
2.5Y = 137.5
Y= 55 km/h
參考: self
收錄日期: 2021-04-12 22:33:31
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20061026000051KK02425