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Homework Help: Rearranging an Equation

  1. Dec 14, 2004 #1
    Hopefully this can be done. It should be relatively simple, I'm just awful at rearranging equations.

    I have: x = 90 - sqrt(100+x^2) - sqrt(100+x)

    I want to find the value of x.

    If someone could guide me through the process I would be eternally grateful. I know there's something about reversing operations, but I get lost in the details. ;)
    Last edited: Dec 14, 2004
  2. jcsd
  3. Dec 14, 2004 #2
    I'm sorry, but I don't see any "b" in the equation.
  4. Dec 14, 2004 #3
    Oops... so sorry. I meant x. I changed it at the last minute. :hangs head in shame:
  5. Dec 14, 2004 #4
    Have you considered squaring the equation and then using the quadratic formula?
  6. Dec 14, 2004 #5


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    Yeah,a geberal advice...But first,he mustput one (either one) of his square roots in the other side of the equation (left,if i'm not mistaking) and then square.He has to square 2 times in all,of course.Let's hope that by squaring twice he won't be gettin'a nasty 4-th order algebraic equation...
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