1. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 1 Homework, Page 626 Find (a) A + B, (b) A - B, (c) -2A, and (d) 3A - 2B. 1.

2. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 2 Homework, Page 626 Find the product AB and BA, or state that a given product is not possible. 5.

3. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 3 Homework, Page 626 Use multiplication to verify the matrices are inverses. 9.

4. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 4 Homework, Page 626 Evaluate the determinant of the matrix. 13.

5. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 5 Homework, Page 626 Find the reduced row echelon form of the matrix. 17.

6. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 6 Homework, Page 626 State whether the system of equations has a solution. If it does, solve the system. 21.

7. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 7 Homework, Page 626 Use Gaussian elimination to solve the system of equations. 25.

8. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 8 Homework, Page 626 Solve the system of equations using inverse matrices 29.

9. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 9 Homework, Page 626 Solve the system of equations by finding the reduced row echelon form of the augmented matrix. 33.

10. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 10 Homework, Page 626 Find the equilibrium point for the supply and demand curves. 37.

11. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 11 Homework, Page 626 Solve the system of equations graphically. 41.

12. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 12 Homework, Page 626 Find the coefficients of the function so its graph goes through the given points. 45.

13. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 13 Homework, Page 626 Find the partial fraction decomposition of the rational function. 49.

14. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 14 Homework, Page 626 Match the function with its graph. 53. c.

15. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 15 Homework, Page 626 Graph the inequality. 57.

16. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 16 Homework, Page 626 Solve the system of inequalities. Give the coordinates of any corner points. 61.

17. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 17 Homework, Page 626 Find the minimum and maximum, if they exist, of the objective function f. 65.

18. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 18 Homework, Page 626 69. The xy-coordinate system is rotated through the angle 45° to obtain the x’y’- coordinate system. (a) If the coordinates of a point in the xy-coordinate system are (1, 2), what are the coordinates in the x’y’-coordinate system? (b) If the coordinates of a point in the x’y’-coordinate system are (1, 2), what are the coordinates in the xy-coordinate system? See example 10, page 588.

19. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 19 Homework, Page 626 73. A stockbroker sold a customer 200 shares of stock A, 400 of B, 600 of C, and 250 of D. The price per share of A, B, C, and D, respectively, are $80, $120, $200, and $300. (a) Write a 1 x 4 matrix N representing the number of shares of each stock. (b) Write a 1 x 4 matrix P representing the share price of each stock. (c) Write a matrix product that gives the total cost of the stock the customer bought.

20. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 20 Homework, Page 626 77. Thompson”s Furniture Store borrowed $650,000 to expand its facilities and extend its product line. Some of the money was borrowed at 4%, some at 6.5%, and the rest at 9%. How much was borrowed at each rate if the annual interest was $46,250 and the amount borrowed at 9% was twice the amount borrowed at 4%?

21. Copyright © 2007 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Slide 7- 21 Homework, Page 626 81. If A is an m x n matrix and B is a p x q matrix, and if AB is defined, what can you conclude about their orders? Explain. If AB is defined, then n = p must be true and the order of the product is m x q.