請幫幫手啦!
回答 (2)
2008-09-04 7:02 am
✔ 最佳答案
有冇打錯?條問題係咪應該係 解方程: (x+1)(x-1)-(x+1)(2x+1)=0?
(x+1)(x-1)-(x+1)(2x+1)=0
(x+1)[(x-1)-(2x+1)]=0
(x+1)(-x-2)=0
x=-1 or x=-2
2008-09-08 6:38 am
(x+1)(x-1)-(x+1)(2x+1)
=(x.x + x -x -1)- (2x.x + 2x + x + 1)
= -x.x - 3x - 2
=(x.x + x -x -1)- (2x.x + 2x + x + 1)
= -x.x - 3x - 2
收錄日期: 2021-04-13 16:02:45
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080903000051KK02502