Create an algebraic equations with the math problem

Question

Mike has 108 dollars to spend on 6 books. After buying them he had 18 dollars. How much did each book cost?

Answer 1

Mike spent $90 on 6 books (108 -18).

Assuming the books are all the same price:

Let b = cost of books

6b = 90

b = 90/6

b = 15

The books cost $15 each.