Question

Find the equation of the line that contains the given points. P1(−8, 5), P2(−8, −5)

Answer 1

$\bf \begin{array}{lllll} &x_1&y_1&x_2&y_2\\ % (a,b) &({{ -8}}\quad ,&{{ 5}})\quad % (c,d) &({{ -8}}\quad ,&{{ -5}}) \end{array} \\\\\\ % slope = m slope = {{ m}}= \cfrac{rise}{run} \implies \cfrac{{{ y_2}}-{{ y_1}}}{{{ x_2}}-{{ x_1}}}\implies \cfrac{-5-5}{-8-(-8)} \\\\\\ \cfrac{-10}{-8+8}\implies \stackrel{und efined}{\cfrac{-10}{0}}$

that simply means, is a vertical line, check the picture below.