Answer:
802
Step-by-step explanation:
802
We need to start from the innermost parenthesis and work our way out.
The first parenthesis is
. These are not like terms because one involves a variable, while the other is a constant term. Two terms are summable if they involve the same power(s) of the same variable(s).
So, we can take one step outwards, and we arrive to the square brackets. We have

and 2z and -13z are like terms, so we can sum them:

Finally we arrive to the whole expression, which is

Because, again, 5z and 11z were like terms.
The GCF for 18 and 45 is 9.
Answer:
(a) 9 buildings
(b) 2^n -1
Step-by-step explanation:
The number of distinct non-empty subsets of b objects is 2^b -1. Since the subsets are distinct, each could represent a list of the buildings, from the set of b buildings, in which a student is taking courses.
(a) For 8 buildings, 2^8 -1 = 255 students could enroll. for 9 buildings, 2^9-1 = 511 students could enroll.
For 500 students, 9 buildings are required.
__
(b) The maximum number of students for n buildings is ...
2^n -1