Solve. LaTeX:  \displaystyle \sqrt{x + 24}=\sqrt{x + 4} - 4

Squaring both sides gives LaTeX:  \displaystyle x + 24=x - 8 \sqrt{x + 4} + 20 . Isolating the radical gives LaTeX:  \displaystyle - \frac{1}{2}=\sqrt{x + 4} Squaring again gives LaTeX:  \displaystyle \frac{1}{4}=x + 4 . Solving for LaTeX:  \displaystyle x gives LaTeX:  \displaystyle x=- \frac{15}{4} . Checking the solution, LaTeX:  \displaystyle x = - \frac{15}{4} , in the original equation gives LaTeX:  \displaystyle \frac{9}{2} = - \frac{7}{2} which is false so it is an extraneous solution and there is no solution.