I have never done this before and I am not sure I am doing this right.

I am taking college algebra online and I am lost in this matrix stuff. I have had several folks try to help me but no one has come up with the correct answer. The sheet I am doing is multiple choice. The two sets of answers that I come up with over and over are not one of the choices. This is what the problem said.

Use elementary row operations to write the matrix below in row echelon form.

1 -4 6 9

3 -11 8 1

2 -5 -3 -15

Please Help !!!