我有maths吾明,
wish可以help 我做啦>u<...
(a+b)2次方-(c+d)2次方=??
(x-y)2次方-(x-z)2次方=??
(3x+2)次方-(2x+1)2次方=??
(5x+2)2次方-(3x-4)2次方=??
(a+b+c)2次方-d2次方=??
Factorisation_FROM2
2009-02-07 6:24 am
回答 (2)
2009-02-07 7:41 am
✔ 最佳答案
You know (a+b)(a-b) = a^2 - b^2 this rule ?(a+b)^2 - (c+d)^2
= [(a+b)+(c+d)][(a+b)-(c+d)]
= (a+b+c+d)(a+b-c-d)
(x-y)^2 - (x-z)^2
= [(x-y)+(x-z)][(x-y)-(x-z)]
= (2x-y-z)(-y+z)
= (2x-y-z)(z-y)
(3x+2)^2 - (2x+1)^2
= [(3x+2)+(2x+1)][(3x+2)-(2x+1)]
= (5x+3)(x+1)
(5x+2)^2 - (3x-4)^2
= [(5x+2)+(3x-4)][(5x+2)-(3x-4)]
= (8x-2)(2x+6)
= 4(4x-1)(x+3)
(a+b+c)^2-d^2
= [(a+b+c)+d][(a+b+c)-d]
= (a+b+c+d)(a+b+c-d)
參考: own working
2009-02-07 6:34 am
You can use the principle a^2 - b^2 = (a + b)(a-b) for all of the questions to get the answers. For example:
1. (a + b)^2 - (c +d)^2 = [(a + b) + (c +d)][(a +b) - (c + d)]
=(a + b+c + d)(a + b - c - d).
3. (3x + 2)^2 - (2x +1)^2 = [(3x +2) + (2x +1)][(3x +2) - (2x +1)]
= (5x + 3)(x +1).
1. (a + b)^2 - (c +d)^2 = [(a + b) + (c +d)][(a +b) - (c + d)]
=(a + b+c + d)(a + b - c - d).
3. (3x + 2)^2 - (2x +1)^2 = [(3x +2) + (2x +1)][(3x +2) - (2x +1)]
= (5x + 3)(x +1).
收錄日期: 2021-04-25 22:36:12
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https://hk.answers.yahoo.com/question/index?qid=20090206000051KK02055