數學...
2006-10-26 4:04 am
a restaurant has launched a promotion campaign: the cost of all dim-sums are reduced from $12.8 eash to only $6.8 each before 11:00a.m. oneday Sandy and her family orderd 20 dishes of dim-sums, and pail $172. if thare is no charge for tea and no service charge , how many dishes of dim-sums did they order befre and after 11:00 a.m. repectively? (回答請中文~)
回答 (2)
2006-10-27 9:38 pm
✔ 最佳答案
1)設11時前的點心數量 = X
11時後的點心數量 = 20-X
6.8x+12.8(20-x)=172
256-6x=172
6x=84
x=14
所以11時前的點心數量是14碟, 11時後的點心數量是20-14=6碟
2)
設 number = Y,
11 times the number = 11Y
subtract 5 from 11 times the number = 11Y - 5
multiply the difference by 2 = (11Y-5)*2
2006-10-26 4:26 am
第一題
設x=11時前叫的點心數量
咁20-x=11時後叫的點心數量
6.8x+12.8(20-x)=172
256-6x=172
6x=84
x=14
咁所以11時前叫的點心數量是14碟
11時後叫的點心數量是20-14=6碟
第二題唔係好明問乜
設x=11時前叫的點心數量
咁20-x=11時後叫的點心數量
6.8x+12.8(20-x)=172
256-6x=172
6x=84
x=14
咁所以11時前叫的點心數量是14碟
11時後叫的點心數量是20-14=6碟
第二題唔係好明問乜
參考: 自己
收錄日期: 2021-04-12 22:31:23
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20061025000051KK03645