Answer:
45n + 60 = 285
Explanation:
n=# of weekday classes (this is an unknown value)
45n= each weekday class is 45 mins long, and when you multiply it by "n" which is the number of weekday classes, you will get a total number of minutes.
+60= we add 60 because that is how many mins it takes for the one class on the saturday. there is only one saturday class which means that you dont need a variable attached to it.
=285
this is the total number of mins from last week.
so, the total number of mins from last week has to equal the 60 min class plus however many 45 min classes there are that week.
45n+60=285
and if you really wanted to know how many weekday classes there were that week, n=5