Respuesta :

Answer:

Add 3, then 5, then 7, then 9, then 11, then 13, then 15, ...

Step-by-step explanation:

-3 + (3) = 0

0 + (5) = 5

5 + (7) = 12

12 + (9) = 21

21 + (11) = ____

____ + (13) =      ,  etc.