21. Consider the following linear program: Max 2A + 3B St. 5A + 5B S 400 Constraint 1 -1A + 1B S 10 Constraint 2 1A + 3B 2 90 Constraint 3 A, B 20 Figure 7.23 shows a graph of the constraint lines. a. Place a number (1, 2, or 3) next to each constraint line to identify which constraint it represents b. Shade in the feasible region on the graph. c. Identify the optimal extreme point. What is the optimal solution? d. Which constraints are binding? Explain. e. How much slack or surplus is associated with the nonbinding constraint? 7.23 GRAPH OF THE CONSTRAINT LINES FOR EXERCISE 21 B 90 80 70 60 50 40 1 30 20 - 10 0 A 10 20 30 40 50 70 60 80 90 100