The cost of meal = 
The tip to the waiter =
%
Discount =
%
Cost = 
Cost = 
Cost = $
0
Answer:


128-72=56
average rate of change is 56
Step-by-step explanation:
Plz let me know if im right
8 costs 40 so 10 costs | 40 / 8 = ( 5*2=10) So your answer is 50 Dollars.