Solve. LaTeX:  \displaystyle \sqrt{x + 12}=\sqrt{x - 6} - 1

Squaring both sides gives LaTeX:  \displaystyle x + 12=x - 2 \sqrt{x - 6} - 5 . Isolating the radical gives LaTeX:  \displaystyle - \frac{17}{2}=\sqrt{x - 6} Squaring again gives LaTeX:  \displaystyle \frac{289}{4}=x - 6 . Solving for LaTeX:  \displaystyle x gives LaTeX:  \displaystyle x=\frac{313}{4} . Checking the solution, LaTeX:  \displaystyle x = \frac{313}{4} , in the original equation gives LaTeX:  \displaystyle \frac{19}{2} = \frac{15}{2} which is false so it is an extraneous solution and there is no solution.