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Math Help - laws of logarithms

  1. #1
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    laws of logarithms

    this question is trickier than i'm used too...a little help please?

    log_{7}(49)(7) + log_{7}\sqrt{7}
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  2. #2
    Senior Member Stroodle's Avatar
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    Hi there.

    log_7 49=2

    so 7log_7 49=7\times2

    and log_7\sqrt{7}=\frac{1}{2}

    So 7log_7 49+log_7 \sqrt{7}=14\frac{1}{2}
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  3. #3
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    Quote Originally Posted by Stroodle View Post
    Hi there.

    log_7 49=2

    so




    i don't understand this part, why did the 7 move to the front of the log?
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  4. #4
    Senior Member Stroodle's Avatar
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    Because it's in a separate bracket to the 49, it means that the logarithm is multiplied by 7. I just put it in front because that's how it is conventionally written (at least in my texts).
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  5. #5
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    Smile

    Quote Originally Posted by Stroodle View Post
    Hi there.

    log_7 49=2

    so 7log_7 49=7\times2

    and log_7\sqrt{7}=\frac{1}{2}

    So +\frac{1}{2}" alt="7log_7 49+log_7 \sqrt{7}=14+\frac{1}{2}" />
    you forgot a sign.
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  6. #6
    Senior Member Stroodle's Avatar
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    Quote Originally Posted by Raoh View Post
    you forgot a sign.
    I don't get it?

    14+\frac{1}{2}=\frac{29}{2}=14\frac{1}{2}
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