Remember how I said that matrix multiplication is NOT commutative? Most of the time?
Try these multiplications:
You should have noticed two funky things:
|You got the same thing for both|
|You got A for both answers!
There was just no getting rid of that guy!
There's a good explanation for both of these things:
That B matrix I gave you is a very special guy -- So special that he gets his own letter and name:
THE IDENTITY MATRIX: