x/3-(20-x)/7=10
更新1:
仲有一題: An amount of $830 is shared among 35 children.Each child of the age 10 years or above can get $25 and each child of the age below 10 can get$16. How many children are of age 10years or above?
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回答 (3)
2009-05-01 7:53 pm
✔ 最佳答案
x/3-(20-x)/7=10 7x-3(20-x)=210
7x-60+3x=210
10x=270
x=27//
Let x be the number of children of the age 10 years or above.
then 35-x be the number of children of the age below 10 。
25x+10(35-x)=830
25x+350-10x=830
15x=480
x=32
∴The number of children of the age 10 years or above=32//
2009-05-04 1:29 am
21(x/3-(20-x)/7)=21*10
7x-3(20-x)=210
7x-60+3x=210
9x=270
x=30
7x-3(20-x)=210
7x-60+3x=210
9x=270
x=30
參考: -----------------------------------------------------
2009-05-01 7:03 pm
x/3-(20-x)/7=10
21(x/3-(20-x)/7)=21*10
7x-3(20-x)=210
7x-60+3x=210
9x=270
x=30
2009-05-01 11:05:39 補充：
為了消去分母所以等式兩邊乘上 3&7 的 L.C.M. 21
21(x/3-(20-x)/7)=21*10
7x-3(20-x)=210
7x-60+3x=210
9x=270
x=30
2009-05-01 11:05:39 補充：
為了消去分母所以等式兩邊乘上 3&7 的 L.C.M. 21
收錄日期: 2021-04-23 20:37:22
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090501000051KK00453