plz help me to naswer the question,if you do not know the answer,plz answer no~I need the step~Thank for your help`!
Expand::
1) (2x+y+1)^2
2) (3x+2)^2(3x-2)^2
3)(x^2+5x+3)(x-2) (arrange the answer in descending powers of x)
4) (2x+3)(2x-3)
5) (x-2)(x+2)(x^2+4)
6) (2x+)(2x-y)
f.2 mathz expand
2007-10-01 8:05 am
回答 (1)
2007-10-01 8:21 am
✔ 最佳答案
1)(2x+y+1)^2=4x^2+2xy+2x+2xy+y^2+y+2x+y+1
=4x^2+4xy+4x+y^2+2y+1
2)(3x+2)^2(3x-2)^2
=(9x^2+2*6x+4)(9x^2-2*6x+4)
=81x^4-108x^3+36x^2+108x^3-144x^2+48x+36x^2-48x+16
=81x^4-72x^2+16
3)(x^2+5x+3)(x-2)
=x^3-2x^2+5x^2-10x+3x-6
=x^3+3x^2-7x-6
4)(2x+3)(2x-3)
=4x^2-6x+6x-9
=4x^2-9
5)(x+2)(x-2)(x^2+4)
=(x^2-4)(x^2+4)
=x^4-16
6)(it's incomplete so I suppose it's (2x+y))
(2x+y)(2x-y)
=4x^2-y^2
收錄日期: 2021-04-13 13:41:34
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https://hk.answers.yahoo.com/question/index?qid=20071001000051KK00032