Answer:
C = F(0.20) + F
Explanation:
C is the total cost. F(0.20) will reduce the value of the food to the tip amount required, and then adds the tip value to the price of the food, F.
Example inputs: let F be equal to 10
C = F(0.20) + F turns into C = 10(0.20) + 10
10(0.20) will cause 10 to be multiplied by the tip value, 20%, and 20% is equivalent to 0.20. Once you multiply 10 by 0.20, you get 2. After that, you add 2 to the price of food, which is 10, and you get a total cost of 12.
12 = 10(0.20) + 10