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Homework Help: Tinkering with equations

  1. Mar 11, 2015 #1
    1. Please could you give me a hand with deriving the following equation:


    2. Relevant equations

    Eq 1: 1/CMC=x1/CMC1+x2/CMC2
    Eq 2: CMC=x1mCMC1+x2mCMC2
    Eq 3: x1+x2=1

    3. The attempt at a solution

    1. invert Eq 2 and equate with Eq 1.
    2. eliminate x2m using the fact that x2m=(1-x1m)
    3. Rearrange..

    I get to the following and don't know how to get closer to the solution. I've got a feeling I'm missing something obvious.


    Please help!

    Thank you in advance.
    Last edited by a moderator: Mar 11, 2015
  2. jcsd
  3. Mar 11, 2015 #2


    Staff: Mentor

    Please show the work that you have done. Telling us a result you have gotten to does not help us understand where you might have gone astray.
  4. Mar 12, 2015 #3
    What are you ultimately trying to solve for?

    You can solve for x1 and x2 immediately by working exclusively with eqns. 1 and 3. The equations are linear.

  5. Mar 12, 2015 #4


    User Avatar
    Science Advisor
    Homework Helper
    2017 Award

    Is based on what, exactly ?

    And: you say you want help in deriving these equations. You mean solving ?
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