Answer:
I believe that the answer is $2.04, per gallon.
Explanation:
I added the $25 he paid with the gift card, and the $26, which was $51 that Corey paid in total. Corey had gotten 25 gallons and they want to figure out how much he paid for each gallon. So we take the total he spent divided by the number of gallons he had gotten. So 51/25=2.04
Hope this helps!!!!