Answer:
2.75g=c
Explanation:
not quite sure what your asking, but this is my best answer you take the 2.75 base cost, add the variable G for the gallons purchased which gives you 2.75g which in the end would give you the total cost (C) giving you the equation 2.75g=c
if this isnt what you were asking id be happy to help if you elaborate more or post the exact question your needing help on