Problem 4.1

[frohro]

In part a) I am not getting what the book claims is the answer. I have the inverse on the opposite side and don't see how to commutate it. See the attachment.
Problem 4.1.pdf On part b, maybe they only meant a single input single output system, but I assumed it should be for a multiple output system. I don't know how to take determinants of non-square matrices, so the book's hint didn't make sense to me, nor does the solution here. Maybe they only meant single input, single output systems.