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Algebraic Manipulation

  1. Mar 19, 2010 #1
    1. The problem statement, all variables and given/known data

    Somehow the upper two statements are manipulated to get the lower one but i cant work out how.... (see attatched image)

    2. Relevant equations


    3. The attempt at a solution

    Oh you dont want to see mypages of scribble. I cant get close to that expression!

    Attached Files:

  2. jcsd
  3. Mar 20, 2010 #2


    Staff: Mentor

    In the first two equations you have expressions that are both equal to VCC/3, so you can equate the two expressions on the left sides.

    Doing that, you can solve for RBB as a constant multiple of RE.

    Then, substitute in either of your first two equations to get the desired equation in VBB, Vf, and VCC.
  4. Mar 21, 2010 #3
    ahh, finally got it... the last time i tried to do it that way i got and extra factor somehow and that's what was messing me up.

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