1.factorize x*2-10x+21
2.factorize(2y+3)*2-20y-9
3.5-40mn+80m*2n*2
4.3a*2-8b+4ab-6a
5.25-(3y-4)*2
*2=2次
唔該....
thx
急用阿
maths~因式分解
2010-09-25 6:16 am
回答 (1)
2010-09-25 6:47 am
✔ 最佳答案
1.x^2-10x+21
=(x-3)(x-7)
2.
(2y+3)^2-20y-9
=(4y^2+12y+9)-20y-9
=4y^2-8y
=4y(y-2)
3.
5-40mn+80m^2n^2
=5[1-8(mn)+16(mn)^2]
=5(1-4mn)^2
4.
3a^2-8b+4ab-6a
=(3a^2+4ab)-(6a+8b)
=a(3a+4b)-2(3a+4b)
=(3a+4b)(a-2)
5.
25-(3y-4)^2
=5^2-(3y-4)^2
=[5-(3y-4)][5+(3y-4)]
=(9-3y)(1+3y)
=3(3-y)(1+3y)
收錄日期: 2021-04-22 00:52:15
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100924000051KK03406