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Math Help - How do I iso late x in the following eqation:

  1. #1
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    How do I iso late x in the following eqation:

    Lr = Hx -Lx -rx -rx

    In other words how do I define x in terms of the other units: x =

    Thanks.
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  2. #2
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    \displaystyle L\,r = H\,x - L\,x - r^2x - r\,x^2

    \displaystyle L\,r = -r\,x^2 + (H - L - r^2)x

    \displaystyle -L = x^2 + \left(\frac{L + r^2 - H}{r}\right)x.


    Now complete the square.
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  3. #3
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    x^2 + Kx + L = 0 where K = (L + r^2 - H) / r

    x = [-K +- sqrt(K^2 - L^2)] / 2

    Isn't that good nuff?
    Last edited by Wilmer; November 27th 2010 at 01:11 AM.
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  4. #4
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    Thanks

    Thanks to both of you. I have forgotten all my school algebra but I will try completing the square and will get back to you if I get stuck. I am 70 and my brain doesn't work like it use to.

    Baz
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