Final answer:
The graph consists of two solid lines representing the constraints where Michael can spend $15 on sandwiches and hot lunches to feed at least three classmates. The solution set is the overlapping shaded area. The point (5, 1) is within the solution set, and an example point (3, 2) means Michael buys 3 sandwiches and 2 hot lunches.
Step-by-step explanation:
Part A: To graph the system of inequalities 2x + 3y ≤ 15 and x + y ≥ 3, you use a two-dimensional coordinate system. For the first inequality, you would draw a straight line corresponding to the equation 2x + 3y = 15, which represents the boundary where Michael spends exactly $15. This line would be solid because the inequality includes values that are equal to 15 as well. The area below and including the line is shaded to represent all the combinations of x (sandwiches) and y (hot lunches) that cost at most $15. For the second inequality, a straight line will be drawn for the equation x + y = 3, representing the fewest number of lunches Michael can buy for his three classmates. As this line represents at least three lunches, it will also be solid, and the area above and including the line will be shaded. The solution set consists of the area where both shadings overlap.
Part B: To determine if the point (5, 1) is included in the solution area, substitute x with 5 and y with 1 into both inequalities. 2(5) + 3(1) ≤ 15 simplifies to 10 + 3 ≤ 15, which is true. The second inequality, 5 + 1 ≥ 3, simplifies to 6 ≥ 3, which is also true. Therefore, the point (5, 1) is in the solution set.
Part C: Choosing the point (3, 2) from the solution set means Michael buys 3 sandwiches and 2 hot lunches. This combination respects both constraints because 2(3) + 3(2) = 12 ≤ 15 and 3 + 2 = 5 ≥ 3, so it fits his budget and feeds at least three classmates.