[tex] \bf (\stackrel{x_1}{-8}~,~\stackrel{y_1}{-16})\qquad
(\stackrel{x_2}{18}~,~\stackrel{y_2}{5})
\\\\\\
slope = m\implies
\cfrac{\stackrel{rise}{ y_2- y_1}}{\stackrel{run}{ x_2- x_1}}\implies \cfrac{5-(-16)}{18-(-8)}
\\\\\\
\cfrac{5+16}{18+8}\implies \cfrac{21}{26} [/tex]
