Liu and Laylands Rate-monotonic scheduling algorithm

I have seminar next week I my OS class. We're supposed to summarize the article below. However it is quite technical & abstract for me and my classmates. I would love if someone could shed some light into the theorems and how they are deducted.

It is suppose to be a really famous article in hard real-time systems, but I would say it's slightly overkill for Bs students to read though.

Article: Liu, C. L.; Layland, J. (1973), "Scheduling algorithms for multiprogramming in a hard real-time environment", Journal of the ACM, 20