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Math Help - evaluating logarithms

  1. #1
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    Post evaluating logarithms

    log2 (x+3) - log2 x = 2

    I know that since this is a subtracting equation, I need to compress this to division. However after that I don't know what to do next.

    log2 (x+3)
    log2 x

    = 2

    How I'm I able to solve for x?
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  2. #2
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by katchat64 View Post
    log2 (x+3) - log2 x = 2

    I know that since this is a subtracting equation, I need to compress this to division. However after that I don't know what to do next.

    log2 (x+3)
    log2 x

    = 2

    How I'm I able to solve for x?
    actually, it is \log_2 \left( \frac {x + 3}x \right) = 2 (review your log rules!)

    Now, just do the anti-log, you get \frac {x + 3}x = 2^2 (since \log_a b = c \Longleftrightarrow a^c = b)

    now solve for x
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