(a) A and B are any matrices with the same number of rows. What can you say (and explain why it is true) about the comparison of rank of A rank of the block matrix [A B] (b) Suppose B = A2. How do those ranks compare? Explain your reasoning. (c) If A is m by n of rank r, what are the dimensions of these nullspaces? Nullspace of A Nullspace of [A A]