# Matrice echelons

2a:
state whether each of the following matrices is in reduced echelon form. If it is not, then give a reason and say what single row operation is needed to bring it to reduced echelon form.

II)

1 1 0 3 0
0 0 1 2 0
0 0 1 2 1
not in reduced echelon form ( don't know how to do this one)
NOT SURE WHAT SINGLE OPERATION will bring to reduced echelon form

III)

1 0 -2 0
0 1 0 0
0 0 0 1
not in reduced echelon form(not sure how to remove the -2)
NOT SURE WHAT SINGLE OPERATION will bring to reduced echelon form

0 1 5 0 1
0 0 0 1 2
0 0 0 0 0
not in reduced echelon form (there is a 5 in the way)
NOT SURE WHAT SINGLE OPERATION will bring to reduced echelon form

VII)

1 4 0 1
0 0 0 0
0 0 1 3
not in reduced echelon form(there is a 4 in the way)
NOT SURE WHAT SINGLE OPERATION will bring to reduced echelon form

Mark44
Mentor
2a:
state whether each of the following matrices is in reduced echelon form. If it is not, then give a reason and say what single row operation is needed to bring it to reduced echelon form.

II)

1 1 0 3 0
0 0 1 2 0
0 0 1 2 1
not in reduced echelon form ( don't know how to do this one)
NOT SURE WHAT SINGLE OPERATION will bring to reduced echelon form
Use the 2nd row to eliminate the 1 in the 3rd row.
III)

1 0 -2 0
0 1 0 0
0 0 0 1
not in reduced echelon form(not sure how to remove the -2)
NOT SURE WHAT SINGLE OPERATION will bring to reduced echelon form
This ***is*** in reduced row echelon form. Check your book to see how RREF is defined and I think you'll see why I'm saying you're done here.
0 1 5 0 1
0 0 0 1 2
0 0 0 0 0
not in reduced echelon form (there is a 5 in the way)
NOT SURE WHAT SINGLE OPERATION will bring to reduced echelon form
Again, check the definition of RREF. You're done here.
VII)

1 4 0 1
0 0 0 0
0 0 1 3
not in reduced echelon form(there is a 4 in the way)
NOT SURE WHAT SINGLE OPERATION will bring to reduced echelon form
Swap rows 2 and 3.