Respuesta :

6) 4r + 8 + 5 = -15 - 3r

4r + 3r = -15 -8 - 5

7r = -28

r = -28/7

r = -4

8) 3n - 15 = 7n + n

-15 = 7n + n - 3n

-15 = 5n

n = -15/5

n = -3