Answer:
r = 66
Step-by-step explanation:
Calculate the slope m using the slope formula and equate to - 4
m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]
with (x₁, y₁ ) = (12, 10) and (x₂, y₂ ) = (- 2, r)
m = [tex]\frac{r-10}{-2-12}[/tex] = [tex]\frac{r-10}{-14}[/tex] , then
[tex]\frac{r-10}{-14}[/tex] = - 4 ( multiply both sides by - 14 )
r - 10 = 56 ( add 10 to both sides )
r = 66
