Question

First Bank charges $4.50 per month for a basic checking account plus $0.15 for each check written. Citizen's Bank charges a flat fee of $9. How many checks would you have to write each month in order for the cost to be the same at both banks?

Answer 1

Let n be the number of checks written. Then, in order to be equal:
4.5+0.15n=9
will tell you the number of checks before costs are equal.