Solve. $LaTeX: \displaystyle \sqrt{x + 18}=\sqrt{x - 4} - 3$

Squaring both sides gives $LaTeX: \displaystyle x + 18=x - 6 \sqrt{x - 4} + 5$ . Isolating the radical gives $LaTeX: \displaystyle - \frac{13}{6}=\sqrt{x - 4}$ Squaring again gives $LaTeX: \displaystyle \frac{169}{36}=x - 4$ . Solving for $LaTeX: \displaystyle x$ gives $LaTeX: \displaystyle x=\frac{313}{36}$ . Checking the solution, $LaTeX: \displaystyle x = \frac{313}{36}$ , in the original equation gives $LaTeX: \displaystyle \frac{31}{6} = - \frac{5}{6}$ which is false so it is an extraneous solution and there is no solution.