Respuesta :

9514 1404 393

Answer:

  9 +7i

Step-by-step explanation:

i^2 = -1, so i^8 = (-1)^4 = 1, and i^5 = (-1)^2×i = i

Then ...

  7i^5 +9i^8 = 7i +9 = 9 +7i