Solve LaTeX:  \displaystyle \log_{15}(x + 3117)+\log_{15}(x + 235) = 5 .

Using logarithmic properties and expanding the argument gives LaTeX:  \displaystyle \log_{15}(x^{2} + 3352 x + 732495)=5 . Making both sides an exponent on the base gives LaTeX:  \displaystyle x^{2} + 3352 x + 732495=15^{5} . Expanding and setting equal to zero gives LaTeX:  \displaystyle x^{2} + 3352 x - 26880=0 . Factoring gives LaTeX:  \displaystyle \left(x - 8\right) \left(x + 3360\right)=0 . Solving gives the two possible solutions LaTeX:  \displaystyle x = -3360 and LaTeX:  \displaystyle x = 8 . The domain of the original is LaTeX:  \displaystyle \left(-3117, \infty\right) \bigcap \left(-235, \infty\right)=\left(-235, \infty\right) . Checking if each possible solution is in the domain gives: LaTeX:  \displaystyle x = -3360 is not a solution. LaTeX:  \displaystyle x=8 is a solution.