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Absolute value, what?

  1. Aug 26, 2010 #1
    Excuse me for my english;

    Decide for all the x so this works out; ((2x-7)/(x3+3))<(9/x)<=x²-5x+9

    where "<=" is the same as "and =".

    Having some troubles getting the right values between (9/x)<=x²-5x+9, but otherwise it's fine..

    hope you can help me!
  2. jcsd
  3. Aug 26, 2010 #2


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    Homework Helper

    For future reference, please use the layout given to you when starting a thread in the homework help section, particularly the "attempt at a solution" part.

    To find where [tex]x^2-5x+9\geq 9/x[/tex] if you multiply through by x2 (a positive number for all real non-zero x) you will end up with a quartic that can be factorized easily using the rational root theorem. It should be easy from there where it's greater than zero.
  4. Aug 26, 2010 #3


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    Staff: Mentor

    Sorry about that Mentallic. I moved his thread to Homework Help from a general math forum, and asked him to post more of his work. I should have posted a note here as well.
  5. Aug 26, 2010 #4


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    Homework Helper

    Oh, no problem :smile:
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