the formula of the slope is
[tex]m=\frac{y2-y1}{x2-x1}[/tex]
where (x2,y2) is a right point from (x1,y1)
on this case the points are the same distance, so we can use any order
[tex]\begin{gathered} m=\frac{-1-7}{3-3} \\ \\ m=\frac{-8}{0} \end{gathered}[/tex]
the slope cannot be calculated because the division between 0 dosnt exist, and the line is a vertical line x=3
the line is
