-8(2x+1)(2x+1)=-64
ans係 -1正負開方8over2
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2008-09-06 7:00 pm
回答 (2)
2008-09-06 7:18 pm
✔ 最佳答案
-8(2x+1)(2x+1)=-64(-16x-8)(2x+1)=-64
-32x^2-16x-16x-8=-64
-32x^2 -32x+56=0
4x^2 + 4x -7 =0
[-4 正負開方4^2 -4(4)(-7)]over [2(4)]
-4正負開方128 over 8
-1正負開方8over2
2008-09-06 9:06 pm
收錄日期: 2021-04-23 20:33:49
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080906000051KK00627