Answer: 3x - 78
Explanation:
Profit or loss is gotten when the cost is subtracted from the revenue. In this situation, the revenue is given as $78.
Let the total number of candy bars bought be x. Since they are sold at $3 each, all the candy bars will cost 2x.
Profit/Loss = Revenue - Cost
= 3x - 78
If we get a negative value, that's a loss and a positive value denotes profit