數學難題()
回答 (4)
2007-11-15 6:56 am
✔ 最佳答案
(x-3)^2-4x^2=x^2-3^2-4x^2
=-3x^2-6
(^2=二次方)
希望幫到你啦^^
2007-11-16 7:00 am
^=次方
(x-3)^2-4x^2
(x-3)(x-3)-4x^2
x^2-3x-3x+9-4x^2
-3x^2-6x+9
So,(x-3)2次方-4x2次方is -3x^2-6x+9
I hope I can help you!! Thank you!!
(x-3)^2-4x^2
(x-3)(x-3)-4x^2
x^2-3x-3x+9-4x^2
-3x^2-6x+9
So,(x-3)2次方-4x2次方is -3x^2-6x+9
I hope I can help you!! Thank you!!
參考: Myself!!
2007-11-15 8:49 am
(x-3)^2 - (4x)^2
= x^2 - 6x + 9 - 16x^2
= -15x^2 - 6x + 9
= -3(5x^2 - 2x + 3)
= -3(5x+1)(x-1)
OR
use the equality of a^2 - b^2 = (a+b)(a-b)
(x-3)^2 - (4x)^2
= (x-3+4x)(x-3-4x)
= (5x+3)(-3x-3)
= (5x+3)(-3)(x-1)
= -3(5x+1)(x-1)
= x^2 - 6x + 9 - 16x^2
= -15x^2 - 6x + 9
= -3(5x^2 - 2x + 3)
= -3(5x+1)(x-1)
OR
use the equality of a^2 - b^2 = (a+b)(a-b)
(x-3)^2 - (4x)^2
= (x-3+4x)(x-3-4x)
= (5x+3)(-3x-3)
= (5x+3)(-3)(x-1)
= -3(5x+1)(x-1)
參考: myself,,,
2007-11-15 8:16 am
ans: -3(5x-3)(x+1)
下面我用*代表2次方:
(x-3)*-(4x)*
= x*-6x+9-16x*
= -15x*-6x+9
= -3(5x*+2x-3)
= -3(5x-3)(x+1)
下面我用*代表2次方:
(x-3)*-(4x)*
= x*-6x+9-16x*
= -15x*-6x+9
= -3(5x*+2x-3)
= -3(5x-3)(x+1)
參考: 自己
收錄日期: 2021-04-13 14:29:59
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071114000051KK04418