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Math Help - Solve for x

  1. #1
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    Solve for x

    x/6 = 6/x-8
    I know the answer is x = 4 + 2 times the square root of 13, but I don't know how to attain it.
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  2. #2
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    Quote Originally Posted by Chuck View Post
    x/6 = 6/x-8
    I know the answer is x = 4 + 2 times the square root of 13, but I don't know how to attain it.
     \frac{x}{6} = \frac{6}{x-8}

     \frac{x(x-8)}{6} = 6

     x(x-8) = 36

     x^2- 8x - 36 = 0

    x = \frac{-b \pm \sqrt{b^2-4ac}}{2a} , where  a = 1, b = -8, c = -36 .
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  3. #3
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    Thank you. I didn't know that formula, but I do now.
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