# Homework Help: Tinkering with equations

1. Mar 11, 2015

### jajajujujojo

1. Please could you give me a hand with deriving the following equation:

x1m=(x1CMC2)/(x1CMC2+x2CMC1)

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.

x1m=[(CMC1/x1)+(CMC2/x2)-CMC2)]/(CMC1-CMC2)

Thank you in advance.

Last edited by a moderator: Mar 11, 2015
2. Mar 11, 2015

### 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.

3. Mar 12, 2015

### Staff: Mentor

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.

Chet

4. Mar 12, 2015

### BvU

Is based on what, exactly ?

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