3 The existence of multiplicative identity For every square matrix A, there
exist an identity matrix of same order such that IA = AI = A Now, we shall verify these properties by examples Example 16 If 
1
1
1
1 3
1
2
3
4
A
2
0
3 , B
0 2
and C
2
0
2
1
3
1
2
1 4
−




−






=
=
= 





−






−
−




, find
A(BC), (AB)C and show that (AB)C = A(BC)