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Math Help - Factorization method

  1. #1
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    Factorization method

    20x^3-68x^2+69x-18=0 Other than trial and error method... is there any way to factorize this faster?
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    Quote Originally Posted by cloud5 View Post
    20x^3-68x^2+69x-18=0 Other than trial and error method... is there any way to factorize this faster?
    The fastest method is to use a Computer Algebra System...

    The one I used got

    20x^3 - 68x^2 + 69x - 18 =\pm(2x - 3)^2(5x - 2).


    If you were going to use the Factor and Remainder Theorems, you would need to substitute x = \frac{2}{5} or x = \frac{3}{2} and find that the polynomial equals 0.
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    Quote Originally Posted by Prove It View Post
    The fastest method is to use a Computer Algebra System...

    The one I used got

    20x^3 - 68x^2 + 69x - 18 = {\color{red}\pm} (2x - 3)^2(5x - 2).


    If you were going to use the Factor and Remainder Theorems, you would need to substitute x = \frac{2}{5} or x = \frac{3}{2} and find that the polynomial equals 0.
    \pm ?
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    Quote Originally Posted by mr fantastic View Post
    \pm ?
    I thought it was weird too, but that's what it said...

    I think it should say

    [\pm(2x - 3)]^2(5x - 2).
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