Respuesta :

Answer:

-9-8i

Step-by-step explanation:

(3+i)+(-12-9i)

3+i-12-9i

3-12+i-9i

-9+i-9i

-9-8i

If you're satisfied with the answer, then please mark me as Brainliest.

-8i-9 I think but i’m not very sure