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Homework Help: Algebraic Manipulation

  1. Mar 19, 2010 #1

    Schniz2

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    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

    N/A

    3. The attempt at a solution

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

    Attached Files:

    Schniz2, Mar 19, 2010
  2. jcsd
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  3. Mar 20, 2010 #2

    Mark44

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    Insights Author

    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.
     
    Mark44, Mar 20, 2010
  4. Mar 21, 2010 #3

    Schniz2

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    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.

    thanks!
     
    Schniz2, Mar 21, 2010
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