Answer:

Step-by-step explanation:
Let x = number of books that Hannah donated
We know that the number of students is 150 and the total number of books is represented by b, we can write that as:
Average number of books donated by each student = 
Now we know that Hannah donated 3 times as much as the average. We can write that as:

Eight below zero would express the value -8, negative eight,
but not 8.
I don't know how to get the answer, but i know the answer is 127.50.