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Homework Help: Factorising Problem

  1. Jan 27, 2010 #1
    1. The problem statement, all variables and given/known data

    It's a calculus problem. But I can get all that, it's just this final bit of factorising the answer that has me stumped. The answer I get is correct (as my calculator factorises it into the same answer as the book has), but I've been looking at it and I can't seem to figure out how to factorise it. So I was wondering if someone could please show the steps / techniques used to factorise this problem:

    2. Relevant equations

    Factorise [itex](32x^3(2x^2 + 1) + 8x(2x^2 + 1)^2)[/itex]

    3. The attempt at a solution

    I tried taking out 8x as the common factor to get to: [itex]8x(4x^2(2x^2 + 1) + (2x^2 + 1)^2))[/itex] but I still can't see any way to further simplify it.

    The answer by the way (according to my calculator / book) is: [itex]8 x (2 x^2+1) (6 x^2+1)[/itex]

  2. jcsd
  3. Jan 27, 2010 #2


    Staff: Mentor

    You can take out 8x(2x2 + 1) from each term. What do you have left?
  4. Jan 27, 2010 #3
    Ah. Gotcha. Thanks!!!
  5. Jan 28, 2010 #4
    8 x (2 x^2+1) (6 x^2+1)
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