Recall that if we have m vectors u₁, u₂, . . . , um in Rⁿ, then we can form the matrix a whose columns are u₁, . . . , Um. let B be the echelon form of A. Most questions have a yes/no answer, but I am mostly interested in your reasons for the answer
B =
[3 0 -1 5]
[0 0 2 -1]
[0 0 0 0]
what is n?
