You are interested in buying a new set of wireless headphones. You have recently started a part-time job where you earn $15 an hour. Write an expression that represents how much money you will earn if you work x number of hour

The expression that represents how much money you will earn if you work x number of hours can be calculated by multiplying the hourly rate ($15) by the number of hours worked (x).

Therefore, the expression is:

15x