Solve. LaTeX:  \displaystyle \sqrt{x + 20}=\sqrt{x + 2} - 3

Squaring both sides gives LaTeX:  \displaystyle x + 20=x - 6 \sqrt{x + 2} + 11 . Isolating the radical gives LaTeX:  \displaystyle - \frac{3}{2}=\sqrt{x + 2} Squaring again gives LaTeX:  \displaystyle \frac{9}{4}=x + 2 . Solving for LaTeX:  \displaystyle x gives LaTeX:  \displaystyle x=\frac{1}{4} . Checking the solution, LaTeX:  \displaystyle x = \frac{1}{4} , in the original equation gives LaTeX:  \displaystyle \frac{9}{2} = - \frac{3}{2} which is false so it is an extraneous solution and there is no solution.