Which of the following condition is not satisfied by a matrix in row echelon form?
1
the first non zero element in each row , called the leading entry, is 1.
2
rows with all zero elements , if any, are below rows having a zero element.
3
each leading entry is in the column to the right of leading entry in the previous row.
4
rows with all zero elements , if any are below rows having a non zero element