請問1/(x+y)(x-y)怎樣變做1/2x(1/(x-y) - 1/(x+y))
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1/(x+y)(x-y)代數問題
2013-06-11 11:32 am
回答 (2)
2013-06-11 7:31 pm
參考: myself :D
2013-06-11 12:45 pm
1/(x - y) - 1/(x + y) = [(x + y) - (x - y)]/(x + y)(x - y)
= 2y/(x + y)(x - y)
so 1/(x + y)(x - y) = (1/2y)[ 1/(x - y) - 1/(x + y)]
or 1/(x + y)(x - y) = (1/2x)[ 1/(x - y) + 1/(x + y)]
= 2y/(x + y)(x - y)
so 1/(x + y)(x - y) = (1/2y)[ 1/(x - y) - 1/(x + y)]
or 1/(x + y)(x - y) = (1/2x)[ 1/(x - y) + 1/(x + y)]
收錄日期: 2021-04-23 23:24:42
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20130611000051KK00020