Octave is a matlab replacement, but from the gnu project.
You can do Elementary Matrices like this:
octave:17> m = [3,-4,2,0;-9,12,-6,0;-6,8,-4,0]
m =
3 -4 2 0
-9 12 -6 0
-6 8 -4 0
octave:18> m(1,:) = m(1, :)/3
m =
1.0000 -1.3333 0.6667 0
-9.0000 12.0000 -6.0000 0
-6.0000 8.0000 -4.0000 0
octave:19> m(2, :) + 9*m(1,:)
ans =
0 0 0 0
octave:20> m(2, :) + (9*m(1,:))
ans =
0 0 0 0
octave:21> m(3,:) + 6*m(1,:)
ans =
0 0 0 0
m = [3,-4,2,0;
-9,12,-6,0;
-6,8,-4,0
]