Solutions to Try Its

1. [latex]\left(3,-7\right)[/latex]

2. [latex]-10[/latex]

3. [latex]\left(-2,\frac{3}{5},\frac{12}{5}\right)[/latex]

Solutions to Odd-Numbered Exercises

1. A determinant is the sum and products of the entries in the matrix, so you can always evaluate that product—even if it does end up being 0.

3. The inverse does not exist.

5. [latex]-2[/latex]

7. [latex]7[/latex]

9. [latex]-4[/latex]

11. [latex]0[/latex]

13. [latex]-7,990.7[/latex]

15. [latex]3[/latex]

17. [latex]-1[/latex]

19. [latex]224[/latex]

21. [latex]15[/latex]

23. [latex]-17.03[/latex]

25. [latex]\left(1,1\right)[/latex]

27. [latex]\left(\frac{1}{2},\frac{1}{3}\right)[/latex]

29. [latex]\left(2,5\right)[/latex]

31. [latex]\left(-1,-\frac{1}{3}\right)[/latex]

33. [latex]\left(15,12\right)[/latex]

35. [latex]\left(1,3,2\right)[/latex]

37. [latex]\left(-1,0,3\right)[/latex]

39. [latex]\left(\frac{1}{2},1,2\right)[/latex]

41. [latex]\left(2,1,4\right)[/latex]

43. Infinite solutions

45. [latex]24[/latex]

47. [latex]1[/latex]

49. Yes; 18, 38

51. Yes; 33, 36, 37

53. $7,000 in first account, $3,000 in second account.

55. 120 children, 1,080 adult

57. 4 gal yellow, 6 gal blue

59. 13 green tomatoes, 17 red tomatoes

61. Strawberries 18%, oranges 9%, kiwi 10%

63. 100 for movie 1, 230 for movie 2, 312 for movie 3

65. 20–29: 2,100, 30–39: 2,600, 40–49: 825

67. 300 almonds, 400 cranberries, 300 cashews