[tex]\bf (\stackrel{x_1}{3}~,~\stackrel{y_1}{-4})\qquad (\stackrel{x_2}{5}~,~\stackrel{y_2}{-4}) \\\\\\ \stackrel{slope}{m}\implies \cfrac{\stackrel{rise} {\stackrel{y_2}{-4}-\stackrel{y1}{(-4)}}}{\underset{run} {\underset{x_2}{5}-\underset{x_1}{3}}}\implies \cfrac{-4+4}{2}\implies \cfrac{0}{2}\implies 0[/tex]
