A roast beef sandwich costs $6.75. A customer buys multiple roast beef sandwiches. Write an equation that represents the situation. Use x to represent the number of roast beef sandwiches. Then determine how many sandwiches the customer buys.
Amount used for payment: 80$
The change received: $19.25
An equation that represents this situation is _____
HELP GIVING A LOT OF POINTS FOR THIS I NEED AN EQUASION!!!