Elementary Matrix: Gaussian Elimination Explained

[EvLer]

Elementary matrix is constructed out of identity for gaussian elimination, it's easier to see it on an example:
if A =
1 2 3
4 5 6
7 8 9
and E
1 0 0
-4 1 0
0 0 1
then EA =
1 2 3
0 -3 -6
7 8 9

so now the problem asks how are rows of EM related to the rows of M if E is
1 1 1
0 0 0
where M is arbitrary any matrix.

thank you in advance.

 

[greisen]

I don't know if I understand you correctly

M will be 3x2 matrix and EM will 2x2 matrix where with a summation of the each row in M - a(11) summation of first row and a(12) of second row. Rest will be zero