Sagot :
Answer:
He bought 16 books
Step-by-step explanation:
cost = flat fee + books * cost per book
133 = 5 +b*8 where b is the number of books
133 = 5+8b
Subtract 5 from each side
128 = 8b
Divide each side by 8
128/8 = 8b/8
16 = b
He bought 16 books