we can get the slope of any straight line by simply using two points.
let's see hmmmmmm this line passes through (0, 14) and hmmmm (7, 10).
[tex]\bf (\stackrel{x_1}{0}~,~\stackrel{y_1}{14})\qquad (\stackrel{x_2}{7}~,~\stackrel{y_2}{10}) \\\\\\ slope = m\implies \cfrac{\stackrel{rise}{ y_2- y_1}}{\stackrel{run}{ x_2- x_1}}\implies \cfrac{10-14}{7-0}\implies \cfrac{-4}{7}[/tex]
