What is this Matrix question asking me to do?

[kostoglotov]

It's from the chapter on Matrix Inverses...

imgur link: http://i.imgur.com/8OhFzgi.jpg

This is the entirety of the exercise. It's not following on from or setting anything else up. That's just number 42...what can I do with this?

 

[mfb]

I don't see a question.

You can show that MM^-1=I in each case.

 

[kostoglotov]

I don't see a question.

You can show that MM^-1=I in each case.

What are the four block matrices at the bottom all about?

 

[mfb]

The matrices above seem to help if you want to invert the block matrices below.