1.3乘27^4n over 81^3n+1 =
2.5^n+3 - 5^n+1 over 3乘5^n =
詳細的解釋
Thank you very much ^ ^
整數指數定律
2011-01-02 6:59 am
回答 (1)
2011-01-02 9:01 am
✔ 最佳答案
1)3(27^4n) / 81^(3n+1)= 3(3^3)^4n / (3^4)^(3n+1)= 3(3^12n) / 3^(12n+4)= 3^(12n+1) / 3^(12n+4)= 3^(12n+1 - 12n-4)= 3^-3= 1/272)[5^(n+3) - 5^(n+1)] / (3 * 5^n)= (5^n) (5^3 - 5) / (3 * 5^n)= (5^3 - 5) / 3= 120/3= 40
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https://hk.answers.yahoo.com/question/index?qid=20110101000051KK01415