The sum of 2 numbers is twice their difference. If one of the numbers is 20, the other one is:• 60• 50• ?
回答 (4)
2008-11-19 1:41 pm
✔ 最佳答案
60 because:60 + 20 = 80
60 - 20 = 40
40*2 = 80
2008-11-19 9:54 pm
let a be the unknown (60 or 50) and b be 20
a+b = 2(a-b)
a+20 = 2(a-20)
a+20 = 2a-40
a-2a = -40-20
-a = -60
a = 60
Therefore, the answer must be 60
a+b = 2(a-b)
a+20 = 2(a-20)
a+20 = 2a-40
a-2a = -40-20
-a = -60
a = 60
Therefore, the answer must be 60
2008-11-19 9:19 pm
60
2008-11-19 9:17 pm
60
收錄日期: 2021-05-01 00:12:10
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https://hk.answers.yahoo.com/question/index?qid=20081119050853AAa2M74