Can someone help me answer this question i am really struggling can you show me working so I can follow along

You may write a vector as either (:1, h, e] er e+ 55+ eE, but be careful: you will lose marks if you unis-write these notations. Suppose matrix product AB is defined. (a) If A is 5 x 19 and B is a column matrix, give the dimensions of B and AB. (b) If A is the identity matrix and B is 13 x 13, what size is A? (c) If A is 14 x 15 and AB is 14 x 17, what size is B?[1! Find the determinant of the matrices below by inspection. Give your reason in each ease. i':; 1: 3: 3 u 0 2 0 0 642 2 14 3 5_g 005 12 4 20 43