教育王國

標題: 求式呀! 唔該! [打印本頁]

作者: crystalwesley 時間: 08-3-18 11:44 標題: 求式呀! 唔該!

There are a total of 30$50-cent coins and $2-coins in a moneybox, and the total value of the coins is $42. How many coins of each denomination are there in the moneybox? (use linear equations )

作者: 布甸仔媽媽 時間: 08-3-18 11:54

原文章由 crystalwesley 於 08-3-18 11:44 發表
There are a total of 30$50-cent coins and $2-coins in a moneybox, and the total value of the coins is $42. How many coins of each denomination are there in the moneybox? (use linear equations ):questi ...

Let X be the quantity of $50cents coins, and Y be the quanity of $2 coins

X + Y = 30

0.5X + 2Y = 42

you need to try to solve the equation by yourself, otherwise you cannot improve your mathematics

作者: 2bzmummy 時間: 08-3-18 12:09

長老，

原文章由 布甸仔媽媽 於 08-3-18 11:54 發表

Let X be the quantity of $50cents coins, and Y be the quanity of $2 coins

X + Y = 30

0.5X + 2Y = 42

you need to try to solve the equation by yourself, otherwise you cannot improve your mathematic ...

作者: 正46 時間: 08-3-18 14:24

長老真係寶刀未老!

原文章由 布甸仔媽媽 於 08-3-18 11:54 發表

Let X be the quantity of $50cents coins, and Y be the quanity of $2 coins

X + Y = 30

0.5X + 2Y = 42

you need to try to solve the equation by yourself, otherwise you cannot improve your mathematic ...

作者: alicetong 時間: 08-3-18 15:33

長老

勁

原文章由 布甸仔媽媽 於 08-3-18 11:54 發表

Let X be the quantity of $50cents coins, and Y be the quanity of $2 coins

X + Y = 30

0.5X + 2Y = 42

you need to try to solve the equation by yourself, otherwise you cannot improve your mathematic ...

作者: sorlo 時間: 08-3-18 17:10

長老真係精靈

作者: vivi_vivi 時間: 08-3-18 21:29

46,

長老的老不可與你的"老"同日而語喎:;pppp: :;pppp:

原文章由 正46 於 08-3-18 14:24 發表
長老真係寶刀未老!

作者: yunman 時間: 08-3-18 22:49 標題: 回覆 #7 crystalwesley 的文章

提示: 作者被禁止或刪除內容自動屏蔽

作者: fungsir 時間: 08-3-18 23:29

Let X be the quantity of $50cents coins,
then the quanity of $2 coins will be 30-X.

0.5X + 2(30-X) = 42
0.5X + 60 - 2X = 42
60 - 1.5X       = 42
60 - 42          = 1.5X

then  X = 12  (the quantity of $50cents coins)

the quanity of $2 coins will be 30-X = 30 - 12 = 18...

This maybe F.1 or F.2 question

can use either 1 or 2 unknown equation

作者: crystalwesley 時間: 08-3-19 21:49

多謝你們的回應呀! 這是中一的數呀! thanks a lot!!!!

作者: Asian 時間: 08-3-30 23:46

goodgood ar~

歡迎光臨教育王國 (/)