展開(-1-x)(-1+x)=?
回答 (3)
2011-09-14 2:52 am
✔ 最佳答案
您好，我是 lop，高興能解答您的問題。(1)
展開 (-1-x)(-1+x)
記住 (x-y)(x+y) = x²- y²,
所以
(-1-x)(-1+x)
= [(-1)+(x)][(-1)-(x)]
= (-1)²- x²
= 1 - x²
(2)
因式分解 1-x^2
記住 x²- y²= (x-y)(x+y) ,
1 - x²
= 1²- x²
= (1+x)(1-x)
參考: Hope I Can Help You ^_^ ( From me )
收錄日期: 2021-04-13 18:14:57
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