Answer:
they made 5 pies
Explanation:
total sold = 40
3 pies from the cafeteria times 5 cut pieces = 15
40 - 15 = 25
25 / 5 = 5
the expression is 5x + 15 = 40
5 is how many slices were cut
15 is the slices from the 3 from the cafeteria
40 is how many were sold
5 is how many were made