α²β²-α²β³-α³β²
更新1:
ans係 -56 但我計到72
更新2:
唔該晒 原來係減數出錯
F.4 maths
回答 (1)
2010-10-11 2:45 am
✔ 最佳答案
α²β²-α²β³-α³β²= α²β²(1 - β - α)= (αβ)² (1 - (α+β))= (8/2)² (1 - (-9)/2)= (16)(1 + 9/2)= 882010-10-10 18:49:11 補充：
更正 :
α²β²-α²β³-α³β²
= α²β²(1 - β - α)
= (αβ)² (1 - (α+β))
= (8/2)² (1 - 9/2)
= (16) (- 7/2)
= - 56
收錄日期: 2021-04-21 22:15:11
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20101010000051KK01263