Solve. $LaTeX: \displaystyle \sqrt{x + 20}=\sqrt{x + 8} - 1$

Squaring both sides gives $LaTeX: \displaystyle x + 20=x - 2 \sqrt{x + 8} + 9$ . Isolating the radical gives $LaTeX: \displaystyle - \frac{11}{2}=\sqrt{x + 8}$ Squaring again gives $LaTeX: \displaystyle \frac{121}{4}=x + 8$ . Solving for $LaTeX: \displaystyle x$ gives $LaTeX: \displaystyle x=\frac{89}{4}$ . Checking the solution, $LaTeX: \displaystyle x = \frac{89}{4}$ , in the original equation gives $LaTeX: \displaystyle \frac{13}{2} = \frac{9}{2}$ which is false so it is an extraneous solution and there is no solution.