將二次多項式寫成二個線性因式的乘積

1.
x² - 4x + 4
= x² - 2(x)(2) + 2²
= (x - 2)²


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2.
4x² + 4x + 1
= (2x)² + 2(2x)(1) + 1²
= (2x + 1)²


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3.
3x² - 4x + 1
= 3x² - 3x - x + 1
= (3x² - 3x) + (-x + 1)
= 3x(x -1) - (x - 1)
= (3x - 1)(x- 1)


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4.
3x² - 5x + 2
= 3x² - 3x - 2x + 2
= (3x² - 3x) + (-2x + 2)
= 3x(x -1) - 2(x - 1)
= (3x - 2)(x- 1)

2014-09-26 14:48:34 補充：
發問時點數已扣除，刪除問題只會損人不利己。

1.(x-2)(x-2)
2.(2x+1)(2x+1)
3.(3x-1)(x-1)
4.(3x-2)(x-1)