試題詳解

19. Consider the linear equation Ax = b with A ∈ . Which of the following statements are true?
(A) If rank = m, then there exists at least one solution.
(B) If rank= n, then there exists exactly one solution.
(C) Ifrank = n, then the column vectors of A are linearly independent.
(D) Ifn ＞ m, then there exists at least one solution.
(E) Ifm ＞ n, then there exists at most one solution.