Simple Q about calculating Nullspace

[11markus04]

When calculating the nullspace of a n x n matrix, after i have reduced the matrix to row echelon form, DO ALL MY PIVOTS HAVE TO BE 1 BEFORE i can distinguish the free variables, and then calculate the vectors that satisfy Ax=0?

 

[HallsofIvy]

No, it really doesn't matter if the pivots are 0. That just makes the arithmetic easier since if they are you don't have to divide.