a^2+b^2
a^2-(-b^2)
(a+(-b)(a-(-b))
(a-b)(a+b)
邊到錯
收錄日期: 2021-04-15 22:17:58
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100730000051KK01269