Respuesta :

Leora03

Answer:

r= 12

Step-by-step explanation:

Slope= [tex] \frac{y1 - y2}{x1 - x2} [/tex]

Using the formula above,

[tex] \frac{r - 3}{ - 5 - 4} = - 1 \\ \frac{r - 3}{ - 9} = - 1 \\ r - 3 = - 1( - 9) \\ r - 3 = 9 \\ r = 9 + 3 \\ r = 12[/tex]