Answer:
C
Step-by-step explanation:
So you already know you do 480 calories for the first 3 miles so it doesnt need to be multiplied by the X amount of extra miles
Now you burn 98 calories per extra mile so for instance (if you did say 2 miles you would want to multiply 98 calories by 2 cause you burn 98 calories per mile)
Lastly, you just ate Y amount of calories so you need to subtract that from the burned calories cause you just now consumed Y amount of calories
So in conclusion, the answer would be C. f(x, y) = 480 + 98x + y