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Homework Help: Confusion on a subtraction problem

  1. Apr 7, 2005 #1
    [tex]\frac{x}{x^2-9} - \frac{1}{2x-6}[/tex]

    When I first worked this problem I found the answer to be:
    [tex]\frac{1}{2x-6}[/tex]

    However, in my English class we had this Vietnamese substitute who took my worksheet and did the problems on it in his head and pointed at the answer I wrote for this problem and walked away. He came back and worked it out in front of me and he got the answer:
    [tex]\frac{1}{2x+6}[/tex]

    Which answer is correct?
     
  2. jcsd
  3. Apr 7, 2005 #2

    dextercioby

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    Science Advisor
    Homework Helper

    He is.

    [tex] \frac{x}{(x-3)(x+3)}-\frac{1}{2(x-3)} [/tex]

    Bring to a common denominator and then simplify.

    Daniel.
     
  4. Apr 7, 2005 #3
    Whoops, I see where I went wrong. Messed up when I subtracted the numerators. :( Thanks for the clarification.
     
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