Jimmy is selling used books at a yard sale. a customer buys 9 books at a cost of $0.75 each and pays with a $20.00 bill. jimmy must determine c, the amount of change in dollars he should give the customer. which equation represents c?

20-0.75c=9
20-0.75-9c
0.75(9)+c+20
0.75+9+20

To find your change, first you must determine how much the customer is paying. To find this, you must multiply the cost of one book by the number of books bought.
$0.75 • 9 = $6.75
To find the change, you must subtract $6.75 from $20. $13.25 is your change.
An example of an equation used to solve this would be
0.75(9) + c = $20

Is there a picture of a graph or whatever that goes along with this?