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Math Help - [SOLVED] Log expansion?

  1. #1
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    [SOLVED] Log expansion?

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    I'm not sure what I'm doing wrong. I've tried pretty much everything I could think of, and I've done well on the other log problems in my homework...

    Heres what I got for an answer, but it is wrong apparently
    xlog10 - logx - log(x^6 + 2) - log(x^8 + 2)

    I'm pretty sure you can't break up the parenthesis (x^6 + 2 etc) so am I doing something wrong with the X on the outside?

    Any help would be so appreciated, thanks!
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  2. #2
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    Why are you subtracting the logs on the bottom? \log_{a}(MN)=\log_{a}M + \log_{a}N
    I would do

     <br />
x \ log \ 10 - [ log \ x + log \ (x^6+2) + log \ (x^8+2)]<br />
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  3. #3
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    Quote Originally Posted by spoken428 View Post
    Why are you subtracting the logs on the bottom? \log_{a}(MN)=\log_{a}M + \log_{a}N
    I would do

     <br />
x \ log \ 10 - [ log \ x + log \ (x^6+2) + log \ (x^8+2)]<br />
    I was under the impression that if you use subtraction, you just end up dividing, and then multiply by the reciprocal of the number, so it'd end up on the bottom of the fraction.

    And that answer didn't work when I plugged it in, but thank you for trying!

    EDIT - I just got it.. I was right the first time, except log10 = 1.... I can't believe it made my answer wrong because I forgot to simplify that part.
    Last edited by ZBomber; September 29th 2009 at 07:48 PM.
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