Let A = [al a2 ... an be an m xn matrix. If the set of vectors { a1, a2, . .., an } in RM is linearly independent, which of the following is/are true? (select all that apply) The matrix equation Ax = 0 has free variables. The rank of A is equal to n, The homogenous system Ax = 0 has only one solution. n'm All columns of A are pivot columns