Respuesta :

Answer:

D

Step-by-step explanation:

Given

F(7) = 13 and F(8) = 21, then

F(9) = F(8) + F(7) = 21 + 13 = 34

konrad509

[tex]f(9)=f(8)+f(7)=21+13=34\implies \text{D}[/tex]