1.Annie spent 3/5 of her money on a book and$14 on some snacks.
After that she had$26 left .How much did she have originally?
2.Mr.lee bought some oranges, but he found that 18 of them were bad
.Later,he sold the rest at$2 each and was paid $372. How many oranges did he buy?
3.In a furniture store ,the price of a chair is reduced by $15.If a company
buys 14 chairs for $910, what was the original price of a chair?
4.Jennifer is 3 times as old as her son this year.2 years later, she will be
38 years old.How old is her son now?
5.Amy's age is two-fifths of her father's age this year.If Amy was15 years
old last year,how old is her father now?
F.1數學我要過程急急急急急要今天內
2010-11-22 12:06 am
回答 (2)
2010-11-22 1:36 am
✔ 最佳答案
你好～～～1) Let the amount of money she had be $y.
y - (3 / 5)y - 14 = 26
y - (3y / 5) = 40
2y / 5 = 40
y = 5 x 40 / 2
y = 100
She had $100 originally.
2) Let the amount of oranges he had bought be y.
2(y - 18) = 372
y - 18 = 186
y = 204
He had bought 204 oranges at first.
3) Let the original price of a chair be $y.
14(y - 15) = 910
y - 15 = 65
y = 80
The original price of a chair is $80.
4) Let her son be y years old.
3y + 2 = 38
3y = 36
y = 12
Her son is now 12 years old.
5) Let the age of her father be y.
(2 / 5)y - 1 = 15
2y / 5 = 16
y = 16 x 5 / 2
y = 40
Her father is now 40 years old.
6) Let the amount of pocket money Jenny gets be $y.
2y = 26 + 3 x 18
2y = 80
y = 40
Jenny gets $40 this month.
希望以上解答可以幫到你～～～～～
參考: Yogi
2010-11-22 12:43 am
1. set y is her all money.
y(3/5)+14+26=y
3y/5+40=y
3y/5=y-40
3y=5y-200
-2y=-200
y=100
2. set y is the orange he have buy.
(y-18)*2=372
2y-36=372
2y=408
y=204
3. set y is the original price of a chair.
(y-15)*14=910
14y-210=910
14y=1120
y=80
4. set y is her son old now.
3y+2=38
3y=36
y=12
5.唔明
y(3/5)+14+26=y
3y/5+40=y
3y/5=y-40
3y=5y-200
-2y=-200
y=100
2. set y is the orange he have buy.
(y-18)*2=372
2y-36=372
2y=408
y=204
3. set y is the original price of a chair.
(y-15)*14=910
14y-210=910
14y=1120
y=80
4. set y is her son old now.
3y+2=38
3y=36
y=12
5.唔明
參考: 自己
收錄日期: 2021-04-15 18:13:57
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20101121000051KK00885