Write the equation out: (total cost: 0.35C[per carton] + 75[delivery charge]) ≤ 500. Subtract 75 on both sides and it would be: 0.35C ≤ 425. Divide 0.35 on both sides and you'll get C ≤ 1214. Therefore, the maximum # of cartons that Elvira can buy is 1214 cartons of milk.
Divide sale price by (1 - percent of discount):
15.75 / (1- 0.15) =
15.75 / 0.85 = 18.53
Answer = $18.53
Answer:

Step-by-step explanation:
We have given integral 

, here
and 
Now first integrate 
So 
Integrating by part



So