Reduced Row Echelon Form (RREF)

A matrix in Row Echelon Form is in reduced row Echelon Form if:

• all leading non-zero elements is a 1.
• each leading 1 is the only non-zero entry in its column.

Example

$$\left[\begin{array}{cccccc}1& 0& 0& 2& 0& 7\\ 0& 1& 0& -1& 0& 3\\ 0& 0& 1& 4& 0& -2\\ 0& 0& 0& 0& 1& 5\\ 0& 0& 0& 0& 0& 0\end{array}\right]$$