Solve LaTeX:  \displaystyle \log_{6}(x + 18)+\log_{6}(x - 1) = 3 .

Using logarithmic properties and expanding the argument gives LaTeX:  \displaystyle \log_{6}(x^{2} + 17 x - 18)=3 . Making both sides an exponent on the base gives LaTeX:  \displaystyle x^{2} + 17 x - 18=6^{3} . Expanding and setting equal to zero gives LaTeX:  \displaystyle x^{2} + 17 x - 234=0 . Factoring gives LaTeX:  \displaystyle \left(x - 9\right) \left(x + 26\right)=0 . Solving gives the two possible solutions LaTeX:  \displaystyle x = -26 and LaTeX:  \displaystyle x = 9 . The domain of the original is LaTeX:  \displaystyle \left(-18, \infty\right) \bigcap \left(1, \infty\right)=\left(1, \infty\right) . Checking if each possible solution is in the domain gives: LaTeX:  \displaystyle x = -26 is not a solution. LaTeX:  \displaystyle x=9 is a solution.