點樣分解呢條因式「2x^2-32」?

👨🏻‍🏫 學術台數學

[匿名]

2007-09-09 9:05 am

點樣分解呢條因式「2x2-32」？（必需列明步驟）

回答 (4)

吳廣德

2007-09-09 9:11 am

✔ 最佳答案

首先要知道一條formula:
x^2 - b^2 = (a+b)(a-b)

so
2x^2 - 32
= 2x^2 - 2(16)
= 2( x^2 - 16)
= 2(x^2 - 4^2)

let a = x, b = 4
then,

= 2(x-4)(x+4) <----answer

參考: 希望幫到你^^

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Lemon Grass

2007-09-09 9:11 am

2x^2 - 32

= 2(x^2 - 16)

= 2(x + 4)(x - 4)

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Tieria

2007-09-09 9:10 am

=2(x^2-16)
冇步驟可言，可直接去答案！

2007-09-09 01:12:12 補充：
sor, 漏了幾步......2x^2-32=2(x^2-16)=2(x^2-4^2)=2(x 4)(x-4)

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him

2007-09-09 9:09 am

2x^2 - 32
= 2(x^2 - 16)
= 2(x^2 - 4^2)
= 2(x - 4)(x + 4)

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