Answer:
The points would be: (0, 40); (1, 35); (2, 30); (3, 25); (4, 20); (5, 15); (6, 10); (7, 5); (8, 0).
Explanation:
Sherry begins with 40 shirts before she sells any. This gives us the point (0, 40), where the x-coordinate is the number of days and the y-coordinate is the number of shirts.
After 1 day, she has sold 5 shirts; this would give her 40-5 = 35 shirts left, giving us the point (1, 35).
After 2 days, she has sold 5(2) = 10 shirts; this would give her 40-10 = 30 shirts left, giving us the point (2, 30).
After 3 days, she has sold 5(3) = 15 shirts; this would give her 40-15 = 25 shirts left, giving us the point (3, 25).
After 4 days, she has sold 5(4) = 20 shirts; this would give her 40-20 = 20 shirts left, giving us the point (4, 20).
After 5 days, she has sold 5(5) = 25 shirts; this would give her 40-25 = 15 shirts left, giving us the point (5, 15).
After 6 days, she has sold 5(6) = 30 shirts; this would give her 40-30 = 10 shirts left, giving us the point (6, 10).
After 7 days, she has sold 5(7) = 35 shirts; this would give her 40-35 = 5 shirts left, giving us the point (7, 5).
After 8 days, she has sold 5(8) = 40 shirts; this would give her 40-40 = 0 shirts left, giving us the point (8, 0).