How do I combine these three different Google Calendars into one?

My main google calendar is the one from my original gmail address. My school has finally made a google calendar with our classes on it but the problem is that I can only view it by adding it under “Friend’s calendars” into the google calendar of my SCHOOL’s provided email address. What I want is to be able to view this classes calendar using my original calendar (confused yet?). I have added my school email address under “Other calendars” in my original calendar, but that won’t show me the classes information since those aren’t directly written into the school email calendar, but are part of the school calendar itself.

I cannot add the school calendar directly to my original calendar because that calendar is private and can only be added by emails ending in my school’s name (@——.edu). Help?!?