１） 化簡２７ｘ３＾３ｎ/ ９＾ｎ
２） (5x+y)^2 - (5x - 2y)(5x + 2y）分解為因式
ｍaths 一問
2007-02-16 10:33 pm
回答 (2)
2007-02-16 10:52 pm
✔ 最佳答案
1) 27 x 3^3n / 9^n = 3^3 x 3^3n / 3^2n = 3^[3(n+1)] / 3^2n = 3^(n + 3)2) (5x + y)^2 - (5x - 2y)(5x + 2y) = (5x + y)^2 - [(5x)^2 - (2y)^2] = (5x)^2 + 10xy + y^2 - (5x)^2 + (2y)^2 = 10xy + 5y^2 = 5y(2x + y)
2007-02-16 10:44 pm
1. ２７ｘ３＾３ｎ/ ９＾ｎ
= 3^3 x 3^3n / 3^2
= 3^ ( 3+3n-2n)
= 3^ (3+n)
2. (5x+y)^2 - (5x - 2y)(5x + 2y）
= (5x+y)(5x+y)-(25x^2-10xy+10xy-4y^2)
= 10xy+5y^2
= 5y(2x+y)
= 3^3 x 3^3n / 3^2
= 3^ ( 3+3n-2n)
= 3^ (3+n)
2. (5x+y)^2 - (5x - 2y)(5x + 2y）
= (5x+y)(5x+y)-(25x^2-10xy+10xy-4y^2)
= 10xy+5y^2
= 5y(2x+y)
收錄日期: 2021-04-23 16:40:36
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https://hk.answers.yahoo.com/question/index?qid=20070216000051KK02151