Question

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:  . What did he define as the variable x?

Answer 1

He used x to represent the number of items in which he bought the fruit bars. The piece of information missing is that we need to know the price, guessing it look like this
(price of FB)x+(price of CB)x=4.12

Answer 2

X is the number of bars that in trip