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Homework Help: Logarithms Questions

  1. Jan 13, 2008 #1
    Just a quick check, I've spend hours trying to crack this. Have I gone the right way about it?

    1. The problem statement, all variables and given/known data
    Solve 5^(x-1)= 4^(1-3x)

    2. Relevant equations

    3. The attempt at a solution

    (x-1)log5 = log4 (1-3x)

    xlog5 - log5 = log4 - 3xlog4

    xlog5 + 3xlog4= log4 + log 5

    x(log5 + 3log4) = log4 + log 5

    x= log4 + log 5/(log5 + 3log4)

    = 0.519( 3dp)

    Many thanks
  2. jcsd
  3. Jan 13, 2008 #2
    Looks correct, and I'm assuming that your actual operation was

    [tex]x=\frac{\log 20}{\log{(5\times4^3)}}[/tex]
  4. Jan 13, 2008 #3
    I see thanks for the feedback
  5. Jan 13, 2008 #4
    If you have a TI, just store your answer and then plug it back into your original equation and see if L=R.
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