F.1 maths
2007-04-06 6:34 am
sam has a number of $1 and $5 coins.It was known that half the number of $1 coins was greater than the number of$5 coins by 2.If the total value of the coins was $32,how many $1 coins and how many $5 coins did Sam have?
回答 (2)
2007-04-06 6:43 am
✔ 最佳答案
let the number of $1 be xnumber of $5 be y
x/2-2=y
x+5y= 32
--> x+ 5(x/2-2)= 32
3.5x=42
x=12
so number of $1 is 12 and number of $5 is 4
參考: myself
2007-04-06 6:49 am
let x be the number of $1 coins
let y be the number of $5 coins
x/2 = y+2
so, x = 2y + 4
Then, number of $1 coins = (2y + 4)
number of $5 coins = y
(2y+4) + 5y = 32
7y + 4 = 32
7y = 28
y=4
x = 2(4) +4
x=12
Therefore, the number of $1 coins is 12 and the number of $5 coins is 4.
let y be the number of $5 coins
x/2 = y+2
so, x = 2y + 4
Then, number of $1 coins = (2y + 4)
number of $5 coins = y
(2y+4) + 5y = 32
7y + 4 = 32
7y = 28
y=4
x = 2(4) +4
x=12
Therefore, the number of $1 coins is 12 and the number of $5 coins is 4.
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原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070405000051KK04754