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Math Help - natural log

  1. #1
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    natural log

    solve the equation for x:

    ln x + ln (x-3) = 0
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  2. #2
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    Quote Originally Posted by algebra2 View Post
    solve the equation for x:

    ln x + ln (x-3) = 0
    use the product property of logs ... \ln{a} + \ln{b} = \ln(ab)

    \ln[x(x-3)] = 0

    change to an exponential equation ...

    x(x-3) = e^0

    x(x-3) = 1

    solve the quadratic equation ... remember that only values of x > 3 are valid.
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  3. #3
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    ln(x) +l(x-3) =0

    ln[x(x-3)] =0

    x(x-3) = e^0

    x(x-3)=1

    x^2 - 3x -1=0 (Use the quadratic formula to find the roots)
    Last edited by CaptainBlack; March 1st 2009 at 09:35 AM. Reason: removed the last steps, so that the OP has the opertunity to do some of the work
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