Solving a matrix using MatLab?

I need help solving the following matrix

>> M = [1 0 2 1 18; 0 -3 -3 0 -8; -2 -3 0 0 -41; -1 0 -1 1 16]

I was able to get it to the following

    >> M = [1 0 2 1 18; 0 1 1 0 2.6667; 0 2.3333 0 -.6667 5.2222; 0 0 1 2 34]

I'm stuck. Anybody willing to help me through this. Thanks in advance

It has to be reduced into RREF. What would my next step be?

Answer 1

[Tobias]

Do you have to do it manually? If you have MATLAB at your disposal, why not just use the rref-command?

rref(M)

^ That should fix your problem

Answer 2

[Amed]

I have to do it manually and rref(M) at the end to show it's in RREF form

[Tobias]

Are you sure you have not made a mistake somewhere? I am not getting the same value as you have in your last step and going onwards from there, probably won't do you any good.

By the way: Use comment and not answer

[Amed]

Error as in what? I'm solving using matlab so i'm not too sure where I went wrong.. I'll start from the beginning and step by step what I do

[Amed]

>> M = [1 0 2 1 18; 0 -3 -2 0 -8; -2 -3 0 0 -41; 1 0 -1 1 16];

>> M2=M;

>> M2(3,:) = M2(3,:)+(2*M2(1,:));

>> M2(4,:) = M2(4,:)-M2(1,:);

>> M3 = M2;

>> M3(3,:) = M3(3,:)+M3(2,:);

>> M3(3,:) = M3(3,:)-M3(2,:);

>> M3(3,:) = M3(3,:)-M3(2,:);

>> M3(2,:) = (-1/3)*M3(2,:)

end I end up with [1 0 2 1 18; 0 1 .6667 0 2.6667, 0 0 6 2 3, 0 0 -3 0 -2];

[Amed]

I'm so lost...

[Amed]

Anybody help, it's due like real soon. I'm stuck in the water on this one

[Amed]

hello, anybody out there?

[Amed]

yoyoyoyoyo