Motor Position Control (State Space Matrix Question)

I have an exam on Monday and haven't been able to get in touch with my lecturer for the topic so I'm in need of a little help understanding plugging the numbers in to a state space matrix.

It's a motor position problem taking into account disturbances.

Standard form is x(dot) = Ax + Bu + Bw

Where Bw is the disturbance.


I've taken a screenshot of the slides I have to show the problem but my problem here is plugging the numbers into a matrix for A. I think I get the 1 in the top right but I'm not quite sure why it's -2 instead of 2. Could anyone explain to me why?

Thank you in advance.



**broken link removed**
**broken link removed**

Nevermind, I think I've cracked it.

If you run into anything else that might be 'interesting' ..... you might post it ....