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Math Help - Quick LOG question!

  1. #1
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    Quick LOG question!

    How do I go about solving this? I know the log rules, I just can't figure it out.

    Question:

    log4(x+2) + log4(x-3) = log(4)9

    THE "4" IN EACH TERM IS THE BASE. NOT LOG 4, LOG BASE 4.
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  2. #2
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by Jeavus View Post
    How do I go about solving this? I know the log rules, I just can't figure it out.

    Question:

    log4(x+2) + log4(x-3) = log(4)9

    THE "4" IN EACH TERM IS THE BASE. NOT LOG 4, LOG BASE 4.
    recall:
    \log_a x + \log_a y = \log_a (xy)

    so combine the left hand side using that formula, then equate the things that are being logged on both sides.
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  3. #3
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    Yeah, I know the rules. I've done that, and I'm not getting the correct answer. =/
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  4. #4
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by Jeavus View Post
    Yeah, I know the rules. I've done that, and I'm not getting the correct answer. =/
    \log_4 (x + 2) + \log_4 (x - 3) = \log_4 9

    \Rightarrow \log_4 [(x + 2)(x - 3)] = \log_4 9

    \Rightarrow (x + 2)(x - 3) = 9

    now solve that quadratic
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  5. #5
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    Ahh, thank you.

    I didn't think it'd go as far as having to use the quadratic equation.
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  6. #6
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by Jeavus View Post
    Ahh, thank you.

    I didn't think it'd go as far as having to use the quadratic equation.
    i'm curious as to what you did after you apply the rule. but never mind
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