x^2+x-1
有咩方法計到？謝！
教我一題因式分解- -+
2006-11-02 8:49 pm
回答 (3)
2006-11-02 9:15 pm
✔ 最佳答案
x^2+x-1 =x^2 + 2x + 1 + x - 1 - 2x - 1 =
(x - 1)^2 - x - 2 =
(x - 1)^2 - (x + 2) =
(x - 1)^2 - [√(x + 2)]^2 =
[ (x - 1) + √(x + 2) ] [ (x - 1) - √(x + 2) ] =
[ x - 1 + √(x + 2) ] [ (x - 1 - √(x + 2) ]
2006-11-02 9:02 pm
唔知係咪咁 :
=x(x+1)-1
=(x-1)(x+1)
=x(x+1)-1
=(x-1)(x+1)
2006-11-02 9:02 pm
x^2+x-1 答案應該是...
x(x+1)-1
希望可以幫到你啦!
2006-11-02 13:06:24 補充：
oh... 原來我仲計少左一步! =3='' too bad~
x(x+1)-1
希望可以幫到你啦!
2006-11-02 13:06:24 補充：
oh... 原來我仲計少左一步! =3='' too bad~
參考: myself
收錄日期: 2021-04-12 18:09:22
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20061102000051KK01247