Solve. LaTeX:  \displaystyle \sqrt{x + 16}=\sqrt{x - 4} - 1

Squaring both sides gives LaTeX:  \displaystyle x + 16=x - 2 \sqrt{x - 4} - 3 . Isolating the radical gives LaTeX:  \displaystyle - \frac{19}{2}=\sqrt{x - 4} Squaring again gives LaTeX:  \displaystyle \frac{361}{4}=x - 4 . Solving for LaTeX:  \displaystyle x gives LaTeX:  \displaystyle x=\frac{377}{4} . Checking the solution, LaTeX:  \displaystyle x = \frac{377}{4} , in the original equation gives LaTeX:  \displaystyle \frac{21}{2} = \frac{17}{2} which is false so it is an extraneous solution and there is no solution.