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  1. #1
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    factorise hayden

    4x^2-4\sqrt{5x}+5
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  2. #2
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    Quote Originally Posted by johnsy123 View Post
    4x^2-4\sqrt{5x}+5
    Assuming a typo and you mean:

    4x^2-4\sqrt{5}x+5=(2x-\sqrt{5})^2

    CB
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  3. #3
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    Quote Originally Posted by johnsy123 View Post
    4x^2-4\sqrt{5x}+5
    I assume this is actually

    4x^2 - 4\sqrt{5}x + 5.


    Remember that (a + b)^2 = a^2 + 2ab + b^2.

    What you have posted is a perfect square, because

    4x^2 - 4\sqrt{5}x + 5 =  (2x)^2 + 2(2x)(-\sqrt{5}) + (-\sqrt{5})^2

     = (2x - \sqrt{5})^2
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