# Math Help - System of Equations

1. ## System of Equations

I need to find out how to solve a system of equations with the given matrix form:

AX=CX+B;

I know I need to make it in the form of X= with inverse of A and C as well as using the identity matrix

What I have guessed at the moment is
X= (I-A)^-1 + (I-C)^-1 + B

I am using excel as I have an equation I have to solve with this but if I can figure out the formula for this I can solve the problem fairly easy.

Thanks!

2. ## Re: System of Equations

Hey Launcher.

Re-arranging we get AX - CX = B which implies (A-C)X = B which implies X = (A-C)^(-1)*B.

3. ## Re: System of Equations

Oh wow thanks! I knew I had to re arrange them one way or another but on my other examples I have had to use the Identity matrix in with my equation to solve the problem. However, X= (A-C)(-1)*B looks like it may do the trick as well! I will try this out in excel with my given equation now and see what I come up with!

This is the equation I am trying to solve for X which is teh x,y,z,w matrix.

4. ## Re: System of Equations

By using excel I got:

x=-5
y=-10
z=5
w=10

Does this look correct?

5. ## Re: System of Equations

Try substituting your X vector back in and see if it checks out.

6. ## Re: System of Equations

Yes looks like it checks out! I just wanted to make sure =]