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Math Help - Logarithmic equations

  1. #1
    Ife
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    Logarithmic equations

    Can i get some help with this equation please??

    Solve the logarithmic equation:


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  2. #2
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    HINT:
    log_5 (5 - 4x) = \frac{{\ln (5 - 4x)}}{{\ln (5)}}\;\& \,\log _{\sqrt 5 } (2 - x) = \frac{{2\ln (2 - x)}}{{\ln (5)}}
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  3. #3
    Ife
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    Ok so i got

    x=\frac{e^2 - 3}{-3}

    is that correct?
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  4. #4
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    Quote Originally Posted by Ife View Post
    Ok so i got x=\frac{e^2 - 3}{-3}
    is that correct?
    How in the world did you get anything like that.
    Form what I gave you it follows that (5-4x)=(2-x)^2.
    Last edited by Plato; July 31st 2009 at 10:18 AM.
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  5. #5
    Ife
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    lol. oh my. i feel so dumb. this is stuff i kno. i don't know whats wrong with me this time.. thanks so much! i totally forgot about the 2. Thanks again.
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  6. #6
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    This is an additional hint only:

    Quote Originally Posted by Ife View Post
    Solve the logarithmic equation:


    From the original equation you can see that the domain is: x \in \left(-\infty, \dfrac54\right)

    Quote Originally Posted by Plato View Post
    ...
    Form what I gave you it follows that (5-4x)=(2-x)^2.
    Quote Originally Posted by Ife View Post
    ... this is stuff i kno. ...
    If you solve the equation Plato gave you you'll get 2 results. Check your solution because only one of the values of x belongs to the domain!
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