Respuesta :

Answer:

= d^3 + d^2 + 12d + 18

Step-by-step explanation:

(d^2 + 6d + 9) + (d^3 + 6d + 9)

= d^2 + 6d + 9 + d^3 + 6d + 9

= d^3 + d^2 + 6d + 6d + 9 + 9

= d^3 + d^2 + 12d + 18