Performing Matrix Operations

Question

Let A = [0, 1, 2, 3], B = [2, 0 , 1, 1], C = 1, 0, 4, 1, 3, -1], D = [0, 0, 1, -1, 2, 1, 1, 3, 0]

For each of the following either state that it is not defined or perform the indicated operation(s).

(a) 4A + 3B

(b) BC

(c) CA

(d) BC + B

(e) C + BC

Answer 1

I assume that A and B are 2 x 2, C is 2 x 3, and D is 3 x 3??

For instance, the first row of A is [0 1] and the second row is [2 3].

If so, then 4A + 3B is 2 x 2 with first row [ 6 4] and second row [11 15]

BC is 2 x 3 with first row [2 0 8] and second row [2 3 3]

CA is undefined since the number of columns of C is not the same as the number of rows of A.

BC + B is undefined since BC and B have different dimensions (2 x 3 vs 2 x 2)

C + BC is 2 x 3 with first row [3 0 12] and second row [3 6 4]