Respuesta :

Answer:

-2r^3+4r^2+12r-4

Step-by-step explanation:

6r^3-2r^2+12r-4-8r^3+6r^2

(6r^3-8r^3)+(-2r^2+6r^2)+12r-4

simplify

-2r^3+4r^3+12r-4