# Homework Help: System of equations

1. Nov 17, 2008

### yoleven

1. The problem statement, all variables and given/known data
I have 6 equations with six unknown variables. Does anyone know the best way to proceed?
I've tried to substitute but it won't work for me.
1.Ax+Bx+.03536F2=0
2.Ay+Cy-212.1+.6124F2=0
3.Bz+Cz-.7071F2-212.1=0
4.-3Bz-4Ay+(5)*212.1+(5)*212.1=0
5.4Ax+5Cz=0
6.5Ax+3Bx-5Cy=0

2. Relevant equations
These are the forces in a bent rod supported at points A,B and C by journal bearings.
equation 1 is$$\Sigma$$Fx=0
2 is $$\Sigma$$Fy=0,etc.
I don't need help with the statics, just with the solving for the unknown variables when so many are involved.

2. Nov 17, 2008

### chaoseverlasting

Matrix equation. But even then, you're going to solve a 6x6 matrix. You make an equation of the form AX=B where B=0 (null matrix) in this case. X contains all your variables (x,y,z, etc) and A contains their coefficients.

3. Nov 17, 2008

### tiny-tim

Hi yoleven!
You can simplify it a lot by starting with the easy one, #5, and then doing #1 and #3.

Start it that way, and see what you get.

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