Question

A line includes the points (10,-5) and (-10,-1). What is the equation in slope intercept form?

Answer 1

$\bf (\stackrel{x_1}{10}~,~\stackrel{y_1}{-5})\qquad (\stackrel{x_2}{-10}~,~\stackrel{y_2}{-1}) \\\\\\ slope = m\implies \cfrac{\stackrel{rise}{ y_2- y_1}}{\stackrel{run}{ x_2- x_1}}\implies \cfrac{-1-(-5)}{-10-10}\implies \cfrac{-1+5}{-20}\implies \cfrac{4}{-20}\implies -\cfrac{1}{5} \\\\\\ \begin{array}{|c|ll} \cline{1-1} \textit{point-slope form}\\ \cline{1-1} \\ y-y_1=m(x-x_1) \\\\ \cline{1-1} \end{array}\implies y-(-5)=-\cfrac{1}{5}(x-10) \\\\\\ y+5=-\cfrac{1}{5}x+2\implies y=-\cfrac{1}{5}x-3$