1. Chapter 11 Inequalities and Linear Programming Additional Example 11.1Additional Example 11.1 Additional Example 11.2Additional Example 11.2 Additional Example 11.3Additional Example 11.3 Additional Example 11.4Additional Example 11.4 Additional Example 11.5Additional Example 11.5 Additional Example 11.6Additional Example 11.6 Additional Example 11.7Additional Example 11.7 Additional Example 11.8Additional Example 11.8 Additional Example 11.9Additional Example 11.9 Additional Example 11.10Additional Example 11.10 Example 1Example 1 Example 2Example 2 Example 3Example 3 Example 4Example 4 Example 5Example 5 Example 6Example 6 Example 7Example 7 Example 8Example 8 Example 9Example 9 Example 10Example 10 New Trend Mathematics - S4B Quit

2. Chapter 11 Inequalities and Linear Programming Additional Example 11.11Additional Example 11.11 Additional Example 11.12Additional Example 11.12 Additional Example 11.13Additional Example 11.13 Additional Example 11.14Additional Example 11.14 Additional Example 11.15Additional Example 11.15 Additional Example 11.16Additional Example 11.16 Example 11Example 11 Example 12Example 12 Example 13Example 13 Example 14Example 14 Example 15Example 15 Example 16Example 16 New Trend Mathematics - S4B Quit

3. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

4. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

5. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.1 Solve the following inequalities and represent the solutions graphically. Solution: Graphical representation:

6. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.1 Graphical representation: Solution:

7. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

8. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.2 Find the least values of three consecutive odd numbers such that 4 times the smallest number is not less than 3 times the largest one. Solution: Let x be the smallest odd number. Then the other two consecutive odd numbers are x  2 and x  4. Since x is an odd number, the least value of x is 13.

9. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

10. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

11. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.3 Solve the following simultaneous inequalities and represent the solutions graphically. Solution: Graphical representation of the solutions:

12. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.3 Graphical representation of the solutions: Solution:

13. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

14. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.4 Solve the following simultaneous inequalities and represent the solutions graphically. Solution: Graphical representation of the solutions:

15. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.4 Graphical representation of the solutions: and Solution:

16. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

17. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.5 Solve the following simultaneous inequalities and represent the solutions graphically. Solution: and Graphical representation of the solutions:

18. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.5 Graphical representation of the solutions: and Solution:

19. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

20. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.6 Solve the following simultaneous inequalities and represent the solutions graphically. Solution:

21. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.6 and Solution:

22. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

23. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Solution: and Graphical representation of the solutions: Additional Example 11.7 Solve the following simultaneous inequalities and represent the solutions graphically.

24. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.7 Solution: Graphical representation of the solutions: and

25. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

26. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

27. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

28. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.8 Solve the inequality 2x  3y  15 < 0 graphically. Solution: The graphical solution of 2x  3y  15 < 0 is shown below.

29. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

30. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

31. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.9 Solve the system of inequalities graphically. Solution: The solutions of the system of inequalities are indicated by the shaded region in the figure.

32. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

33. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

34. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.10 Solve the system of inequalities graphically. Solution: The solutions of the system of inequalities are indicated by the shaded region in the figure.

35. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

36. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

37. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.11 Solve the following system of inequalities graphically. Solution: Since x and y are integers, only the coordinates of the points represented by the dots in the figure are the solutions.

38. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

39. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

40. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.12 There are x standard rooms and y deluxe rooms on a floor of a hotel. The floor area of each standard room is 20 m 2 and that of each deluxe room is 30 m 2. In order to satisfy the demand, the number of standard rooms should not be more than 2 times that of deluxe rooms, and the total number of rooms on that floor should not exceed 50. It is known that and the total floor area of the rooms is at most 1 200 m 2. Write down all the constraints about x and y. Solution: The constraints are which are equivalent to

41. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

42. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

43. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

44. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.13 Martin wants to prepare fruit juice A and B for a party with 4 L of pineapple juice and 6 L of orange juice. Fruit juice A and B are prepared by mixing pineapple juice and orange juice in the ratios of 1 : 1 and 3 : 5 respectively. It is known that the amount of fruit juice B prepared should be at least twice that of fruit juice A. Let x L and y L be the amounts of fruit juice A and B prepared respectively. (a)Write down all the constraints about x and y. (b)Find the feasible solutions graphically.

45. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Solution: (a)The constraints are which are equivalent to Additional Example 11.13

46. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit (b) The shaded region in the figure indicates all the feasible solutions. Solution: Additional Example 11.13

47. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

48. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

49. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.14 Find the maximum and minimum values of each of the following functions subject to the system of inequalities in Example 14. (a)f(x, y)  x  2y (b)g(x, y)  x  y Solution: (a)At (  1, 2), f (  1, 2)   1  2(2)  3. At (2, 1), f (2, 1)  2  2(1)  4. At (3, 5), f (3, 5)  3  2(5)  13.  (b)At (  1, 2), g (  1, 2)   1  2   3. At (2, 1), g (2, 1)  2  1  1. At (3, 5), g (3, 5)  3  5   2. 

50. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

51. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

52. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

53. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

54. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.15 A salt plant operates 16 hours a day to produce x bags of table salt and y bags of coarse salt. It is known that at least 900 bags of table salt and coarse salt should be produced everyday and the amount of coarse salt produced should be at least 3 times that of the table salt. To produce a bag of table salt and a bag of coarse salt, 60 seconds and 30 seconds are required respectively. (a)Write down all the constraints about x and y. (b)Draw and shade the region which satisfies all the constraints. (c)If the profit of producing a bag of table salt is 2.5 times as much as that of coarse salt, how many bags of table salt and coarse salt should be produced in order to maximize the profit?

55. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.15 Solution: which are equivalent to (a)The constraints are

56. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.15 (c)Let the profit of producing a bag of coarse salt be $k (where k > 0), then the profit of producing a bag of table salt is $2.5k. Therefore, total profit From the graph the total profit is at the maximum when x  384, y  1 152. (b) The feasible solutions are all integral solutions in the shaded region. Solution:

57. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

58. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

59. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example

60. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.16 A shop sells two different stationery sets A and B. The relevant data of the two sets are as follows: Mr. Chan needs to buy at least 150 notebooks, 100 correction pens and 240 pens with at most $5 000. Let x and y be the respective number of packs of sets A and B to be bought. (a)Write down all the constraints about x and y. (b)Draw and shade the region which satisfies all the constraints. (c)What is the most economical way to buy the required stationery? Find the minimum cost.

61. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.16 Solution: which are equivalent to (a)The constraints are

62. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit Additional Example 11.16 (b) The feasible solutions are all integral solutions in the shaded region. Solution:

63. Chapter 11 Inequalities and Linear Programming 2004 Chung Tai Educational Press © Quit (c)Cost c(x, y)  $(25x + 20y)  The minimum value is attained at B(25, 75).  Minimum cost Solution: Additional Example 11.16