(1) 1/3s+1/7=1/9(2s+3)
(2) 0.2(3y-1)=4+0.3y
(3) The cost of a keyboard is $20 more than that of a mouse.If Nelason
buys 8 mouses , he has to pay $10 less than buying 5 keyboards.
How much is a keyboard?
求未知數(要過程)!!主要解第三題!!!!!!!!!Thank YOU!!!!
2007-11-08 3:15 am
回答 (1)
2007-11-08 4:03 am
✔ 最佳答案
(1) 1/3s+1/7=1/9(2s+3)1/3s+1/7=2/9s+1/3
1/3s-2/9s=1/3-1/7
1/9s=4/21
s=12/7
(2) 0.2(3y-1)=4+0.3y
0.6y-0.2=4+0.3y
0.6y-0.3y=4+0.2
0.3y=4.2
y=14
(3)Let y be the cost of each mouse
8y=(y+20)5-10
8y=5y+100-10
8y-5y=100-10
3y=90
y=30
The cost of a keyboard is:
30+20
=$50
參考: meself
收錄日期: 2021-04-23 22:47:16
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071107000051KK03002