Anthony purchased 6 fruit bars and 3 chocolate-nut bars for a camping trip. He spent $4.12 on the bars. Anthony wrote the following equation: 6x+3y=4.12. What did he define as the variable x?

He defined variable x as the cost of each fruit bar.

Step-by-step explanation:

6 is the amount of fruit bars Anthony has, so 3y must be for the chocolate-nut bars. So the only thing that makes sense is if variable x is the cost of each fruit bar.