Respuesta :

Sanarah
-4 = [tex] \frac{r}{20} [/tex] - 5
[tex] \frac{r}{20} [/tex] - 5 = -4 (Switched sides)
([tex] \frac{r}{20}[/tex] - 5)20 = (-4)20 (Multiply both sides by 20)
r-100 = -80
r - 100 + 100 = -80 + 100 (Add 100 to each side)
r = 20

Hope this helped :)