9. 0.78

11. 0.7

13. $-1.7$

15. 7.3

17. ${\displaystyle \frac{16}{3}}$

19. 0.56

21. $\text{ln }(x)+\text{ln }(x-1)$

23. $\text{ ln }(x+1)-2\text{ ln }(x-2)$

25. ${\displaystyle \frac{1}{2}}{\log }_{a}x+3{\log }_{a}y$

27. ${\displaystyle \frac{1}{3}}{\log }_{a}x-{\displaystyle \frac{1}{3}}{\log }_{a}y$

29. ${\displaystyle \frac{1}{4}}{\log }_{2}x+{\displaystyle \frac{1}{2}}{\log }_{2}y-{\displaystyle \frac{3}{4}}$

31. ${\displaystyle \frac{1}{2}}\log (x^2+1)-\log (x+3)$

33. ${\log }_3(x-1)+{\log }_3(x+1)-{\log }_3(x-2)-{\log }_3(x+2)$

35. $2{\log }_{b}x+3{\log }_{b}y+{\log }_{b}z$

37. $\text{ln }x+{\displaystyle \frac{1}{2}}\text{ ln }(x-1)-\text{ln }(x^2+2)$

39. $2\text{ ln }(x+1)-\text{ln }(x-3)-{\displaystyle \frac{1}{2}}\text{ ln }(x+4)$

41. $\text{ln }(x+1)+{\displaystyle \frac{1}{2}}\text{ ln }(x^2+2)-{\displaystyle \frac{1}{2}}\text{ ln }(x^2+5)$

43. $3\text{ ln }x+4\text{ ln}(3x+1)-{\displaystyle \frac{1}{2}}\text{ ln}(x^2+1)+5\text{ ln}(x+2)-2\text{ ln}(x-3)$

45. ${\log }_2(7x)$

47. $\log {\displaystyle \frac{3x+2}{x}}$

49. ${\ln y}^2\sqrt{x}$

51. $\log \left({\displaystyle \frac{z\sqrt{x}}{y}}\right)$

53. ${\log }_2{(z{y}^2)}^{1/5}$

55. $\text{ln }(x{y}^2{z}^3)$

57. $\log {\displaystyle \frac{x^3\sqrt{x^2+4}}{y}}$

59. $\text{ln }\left({\displaystyle \frac{x^2}{\sqrt{x^2+1}}}\right)$

61. $1.4036\cdot {10}^{217}$

63. $9.3762\cdot {10}^{1897}$

65. ${234}^{567}$

67. 362

69. 2.322

71. $-1.585$

73. 1.760

75. 3.6

77. ${\displaystyle \frac{1}{2}}$

79. 1

81. 18

83. 2

85. $y=2-\log x$

87. $y=2-\text{ln }x$

89. $y=1+3{\text{ log}}_{5}x$

91. $y=-1+5{\text{ log}}_{2}x$

93. $\approx 10.7$ yr

95. $\approx 10.4$ hr