M(n N), then if the coecient matrix is row reduced to reduced rowechelon form which is just the identity matrix In , a unique solution to the system...

M(n N), then if the coecient matrix is row reduced to reduced rowechelon form which is just the identity matrix In , a unique solution to the system of equations will exist. REMARK 3.4 Notice that the rst reduction step in nding the solution to the set of linear equations in Example 3.3, was to interchange the rst and second rows on the augmented matrix. Why was this simple interchange made?