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Quadratic inequality

  1. Sep 24, 2015 #1
    1. The problem statement, all variables and given/known data

    As attached

    2. Relevant equations

    3. The attempt at a solution

    The answer is stated as option A.

    However, my solution is -6≤x≤3;
    I can seems to find an option that fits the solution.

    Attached Files:

  2. jcsd
  3. Sep 24, 2015 #2
    I agree. The question is wrong.
  4. Sep 24, 2015 #3


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    Homework Helper

    Your solution looks solid. There must be a problem with the question. Just trying values in the options show that you are correct.
    7: 49 < 18-21 -- Nope.
    -7: 48 < 18+21 -- Nope.
    4: 16 < 18-12 -- Nope.
    You can rule out all the options on the page.
  5. Sep 24, 2015 #4


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    Staff Emeritus
    Science Advisor
    Homework Helper

    Man, you've been having a string of bad luck with your textbooks containing faulty problems. If the problems are this bad, I wonder if the material is equally flaky?
  6. Sep 26, 2015 #5


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    Gold Member

    Agreed, those options are wrong (and your solution is correct). There's probably a typo in either B or C.
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