The instruction is that "A written statement (1 page) presenting a strong argument for substituting a graduate level core course." In this essay, I need to show what did I learned from these two classes, and why the graduate courses can be waived. For example, I have already learned the knowledge, and can use it very well when I am working. This is one of the reason that why I don't need to take the graduate courses.
So the first part is what I have learned from the two classes, and the second part is why I don't need to learn the graduate course.