Solve LaTeX:  \displaystyle \log_{12}(x + 234)+\log_{12}(x + 1015) = 5 .

Using logarithmic properties and expanding the argument gives LaTeX:  \displaystyle \log_{12}(x^{2} + 1249 x + 237510)=5 . Making both sides an exponent on the base gives LaTeX:  \displaystyle x^{2} + 1249 x + 237510=12^{5} . Expanding and setting equal to zero gives LaTeX:  \displaystyle x^{2} + 1249 x - 11322=0 . Factoring gives LaTeX:  \displaystyle \left(x - 9\right) \left(x + 1258\right)=0 . Solving gives the two possible solutions LaTeX:  \displaystyle x = -1258 and LaTeX:  \displaystyle x = 9 . The domain of the original is LaTeX:  \displaystyle \left(-234, \infty\right) \bigcap \left(-1015, \infty\right)=\left(-234, \infty\right) . Checking if each possible solution is in the domain gives: LaTeX:  \displaystyle x = -1258 is not a solution. LaTeX:  \displaystyle x=9 is a solution.