How to work out these control system examples?

here are the questions:


http://files.engineering.com/download.aspx?folder=4f4a9a93-0a08-4fc5-bb79-a92b01c091ce%26amp;file=questions.jpgHow to work out these control system examples?
Each of these are a feedback loop system. For control boxes next to each other you simply multiply them together. If they are over each other and the one loops backwards then you get (see the link below for photos/better explanation with images)








In my classes we had the same set-up usually:


G is over H for the closed loop system


the open loop system would be G/(1+GH)





For a Unity feedback look, that is, there is no function on the bottom and it's just a simply feedback loop, then H=1 and you have G/(1+G)





The fun part comes when you are supposed to use laplace transforms to solve them all out ;)