Explain how to write and solve the equation to solve the problem.Bella saved enough money to buy 3 books. If each book cost $13, how much money did Bella save?

Answer:

First, define a variable. Let x represent the total amount of money Bella saved. Since she bought 3 books and each cost 13, you can write the equation x/3 = 13, because the total amount divided by the number of books equals the unit price. To solve for x, undo the division by multiplying both sides of the equation by 3. This gives x = 39. Therefore, Bella saved $39.