[tex]\text{Hey there!}[/tex]
[tex]\text{The formula is:}\bf{\frac{y_2-y_1}{x_2-x_1}}[/tex] [tex]\text{ or you can say}\rightarrow[/tex] [tex]\frac{Rise}{Run}[/tex]
[tex]\text{y}_2=-9\\\\\text{y}_1=6\\\\\text{x}_2=12\\\\\text{x}_1=12[/tex]
[tex]\text{Now, that we know what our points are we could solve this equation}[/tex]
[tex]\frac{-9-6}{12-12}[/tex]
[tex]\text{-9 - 6 = -15}[/tex]
[tex]\text{12 - 12 = 0}[/tex]
[tex]\bf{= \ \frac{-15}{0}}[/tex]
[tex]\boxed{\boxed{\bf{Answer: \ \frac{-15}{0}}}}\checkmark[/tex]
[tex]\text{Good luck on your assignment and enjoy your day!}[/tex]
~[tex]\frak{LoveYourselfFirst:)}[/tex]