Respuesta :

It is 7 , 21
That’s the answer
Explenatkon.

Answer:

Maybe    9     and 12   ?

Step-by-step explanation:

-6 + 9 = 3  

    then   3 + 9 = 12

           then 12 + 3 = 15      

                 each term is the sum of the two that are before it