幫手解以下問題:
(5^2a-1)-5^2a-2 /( 5^2a+1)-5^2a-1
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指數函數Q. (F.4) 一題easy
2012-02-04 10:32 am
回答 (2)
2012-02-04 12:45 pm
✔ 最佳答案
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參考: miraco
2012-02-04 6:10 pm
Factorizing 5^(2a) from the numerator and the denominator,
the numerator is 5^(2a)[ 5 - 5^(-2)] = 5^(2a)[5 - 1/25]
the denominator is 5^(2a)[5 - 5^(-1)] = 5^(2a)[5 - 1/5]
eliminating 5^(2a) we get
(5 - 1/25)/(5 - 1/5)
= [(125 - 1)/25]/[(25 - 1)/5]
= (125 - 1)/5(24)
= 124/120
= 31/30
the numerator is 5^(2a)[ 5 - 5^(-2)] = 5^(2a)[5 - 1/25]
the denominator is 5^(2a)[5 - 5^(-1)] = 5^(2a)[5 - 1/5]
eliminating 5^(2a) we get
(5 - 1/25)/(5 - 1/5)
= [(125 - 1)/25]/[(25 - 1)/5]
= (125 - 1)/5(24)
= 124/120
= 31/30
收錄日期: 2021-04-25 22:38:10
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20120204000051KK00109