Chapter 6 - Exponential, Logarithmic, And Inverse Trigonometric Functions - 6.1 Exponential And Logarithmic Functions - Exercises Set 6.1 - Page 419: 23

$$x = \sqrt {3/2} $$

$$\eqalign{ & \ln \left( {1/x} \right) + \ln \left( {2{x^3}} \right) = \ln 3 \cr & {\text{use the product property for logarithms}} \cr & \ln \left( {\frac{{2{x^3}}}{x}} \right) = \ln 3 \cr & {\text{simplify}} \cr & \ln \left( {2{x^2}} \right) = \ln 3 \cr & {\text{then}}{\text{,}} \cr & 2{x^2} = 3 \cr & {x^2} = 3/2 \cr & x = \sqrt {3/2} \cr} $$