I only need help with the extra credit question not question

I only need help with the extra credit question, not question 1. Please show steps and elaborate.

Solution

a)

C^TA

C has size 3x2

C^T has size 2x3

A has size 3x3

Since number of columns of C^T= number of rows of A

SO, C^TA is possible. Its dimension is 2x3

FOr XY with X of size:rxs and Y of size txu,XY has size rxu and is possible if and only if u=r

b)

Ba

B has size 3x3

A has size 1x3

So Ba is not possible possible

c)

ba

b has size 3x1

a has size 1x3

So ba is possible

It has size 3x3