a. Express each column vector of AB as a linear combination of the column vectors of A. b. Express each column vector of BA as a linear combination of the column vectors of B. 46144140 B = 2 3 A = -1 2 9 D = 1 5 2 608 E 9 3 2 4 C = -1 3 6 1 3 -1 1 2 4 1 3 2 5 9