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Homework Help: Algebraic Step

  1. Jan 19, 2005 #1
    Hello


    I do not understand how to get from:

    [tex] (x^2+1)^3 6x^2(x^3 - 1) + (x^3-1)^2 6x(x^2+1)^2 [/tex]

    to [tex] 6x(x^2+1)^2(x^3-1)(2x^3 + x - 1) [/tex]

    I tried factoring the [tex] 6x [/tex] but have had no luck.

    Any help is appreciated!

    Thanks
     
    Last edited: Jan 19, 2005
  2. jcsd
  3. Jan 19, 2005 #2
    try factoring 6x rather than 6x^2
     
  4. Jan 19, 2005 #3

    Hurkyl

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    Well, you can't factor 6x^2, because the second term doesn't have an x^2!

    Here, you're just trying to apply the distributive rule in reverse:

    ab + ac = a(b + c)

    What you need to do is identify the factors that appear in both terms. (e.g. x appears in both terms, but not x^2), and that's what you factor out. (that's the a).
     
  5. Jan 19, 2005 #4

    dextercioby

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    You can't factor [itex] 6x^{2} [/itex],without getting something really ugly...

    Pay attention with the calculations.The fact that u know the result already might help u if u don't see means of factorization...

    Daniel.
     
  6. Jan 19, 2005 #5

    Curious3141

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    [tex] (x^2+1)^3 6x^2(x^3 - 1) + (x^3-1)^2 6x(x^2+1)^2 = (6x)(x^3 - 1)(x^2 + 1)^2\left( (x(x^2 + 1) + (x^3 - 1) \right) = 6x(x^2+1)^2(x^3-1)(2x^3 + x - 1) [/tex]

    Just group the terms and play with the algebra. :smile:
     
  7. Jan 19, 2005 #6

    Hurkyl

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    Pfft, don't do the work for him -- one learns more when they do the work, rather than observing someone else's work.
     
  8. Jan 19, 2005 #7

    Curious3141

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    Point taken :smile:
     
  9. Jan 19, 2005 #8

    dextercioby

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    So much for my advice... :frown:

    Not to mention u messed up the page layout... :grumpy:

    Daniel.
     
  10. Jan 19, 2005 #9
    (he does the work (singular) )

    anyway i worked it out (like 1:20 AM here)

    Thanks all
     
  11. Jan 19, 2005 #10

    Curious3141

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    Then set your browser differently. :tongue2: :rofl:
     
  12. Jan 19, 2005 #11
    Up the resolution, it's just fine on 1280x1024 :P
     
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