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Math Help - Logarithms - help please!

  1. #1
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    Logarithms - help please!

    Log3x – log3 (x-5) = log3 A
    Express A in terms of x.
    Hence, solve the equation
    Log3 x – log3 (x-5) = 1

    Thank you so much.
    Last edited by Jhevon; December 24th 2009 at 12:09 PM. Reason: Restored deleted post
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  2. #2
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    every single 3 is a base, it just didn't show up.
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  3. #3
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by kayteee92 View Post
    Log3x log3 (x-5) = log3 A
    Express A in terms of x.
    Hence, solve the equation
    Log3 x log3 (x-5) = 1

    Thank you so much.
    Recall that \log_a X - \log_a Y = \log_a \frac XY

    So that,

    \log_3 x - \log_3 (x - 5) = \log_3 A

    \Rightarrow \log_3 \frac x{x - 5} = \log_3 A

    Now what?
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  4. #4
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    oh okay, so next i did

    A = x/x-5

    and i crossed multiplied to get x = A(x-5)

    but for the next part of the problem, i replaced this for x and now i am stuck.

    Your help is much appreciated!
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  5. #5
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by kayteee92 View Post
    oh okay, so next i did

    A = x/(x-5)
    stop there. that is A in terms of x.

    but for the next part of the problem, i replaced this for x and now i am stuck.

    Your help is much appreciated!
    for the second part, A = 1. so...?
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  6. #6
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    thank you very much!
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