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Math Help - algebra with logs

  1. #1
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    algebra with logs

    I need help solving this.. i've tried everything, and i havent' gotten too far with it. i tried changing it to base10 but still didn't get anywhere..

    Solve for x

    log3(x - 5) + log3(x + 3) = 2
    Last edited by snypeshow; November 9th 2009 at 09:48 AM.
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  2. #2
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    Use log rules to convert the left-hand sides of the equations to one log term.

    For the first exercise, convert the resulting log equation to the equivalent exponential form, and solve. For the second, you'll have "log(something) equals log(something else)", so set (something) equal to (something else), and solve.
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  3. #3
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    so i can change the first part to:

    = log3 [(x-5)(x+3)]
    = log3( x^2-2x-15)
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