Expand the following.(Show clear step)
1. 3x^2 - (x-1)^2
2. (x+2)^2 - (x-2)^2
Maths!!!
2008-11-03 1:25 am
回答 (3)
2008-11-03 1:28 am
✔ 最佳答案
1)3x^2-(x-1)^2
= 3x^2 - ( x^2-2x+1)
= 2x^2 + 2x - 1
2)
(x+2)^2 - (x-2)^2
= (x+2+x-2)(x+2-x+2)
= (2x)(4)
= 8x
參考: MY BRAIN
2008-11-03 11:22 pm
1. 3x² - (x-1)²
= 3x² -(x²-2x+1).............(a-b)²=a²-2ab+b²
=3x² -x²+2x-1
=2x²+2x-1
2. (x+2)² - (x-2)²
=(x+2+x-2)(x+2-x+2).........a²-b²=(a+b)(a-b)
=(2x)(4)
=8x
= 3x² -(x²-2x+1).............(a-b)²=a²-2ab+b²
=3x² -x²+2x-1
=2x²+2x-1
2. (x+2)² - (x-2)²
=(x+2+x-2)(x+2-x+2).........a²-b²=(a+b)(a-b)
=(2x)(4)
=8x
參考: 會考數學拿c既人~
2008-11-03 1:30 am
1)
3x^2-(x-1)^2
= 3x^2 - ( x^2-2x+1)
= 2x^2 + 2x - 1
2)
(x+2)^2 - (x-2)^2
= (x+2+x-2)(x+2-x+2)
= (2x)(4)
= 8x
Can I Help You?
3x^2-(x-1)^2
= 3x^2 - ( x^2-2x+1)
= 2x^2 + 2x - 1
2)
(x+2)^2 - (x-2)^2
= (x+2+x-2)(x+2-x+2)
= (2x)(4)
= 8x
Can I Help You?
參考: ME ME ME ME
收錄日期: 2021-04-29 16:20:39
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