My son and I are stuck on this one. Can anyone give some insight to this problem? Thank you.

Answer:
I made is clear for you, now you may match each one
Step-by-step explanation:
f(1)= 11, f(n)= 3*f(n-1)
⊕ middle
f(1)= -18, f(n)= f(n-1)+21
f(1)= -18, f(n)= f(n-1) + 22
f(1)= -18, f(n)= 2*f(n-1)
⊕ bottom
f(1)= -18, f(n)= 6*f(n-1)
⊕ top
f(1)= 11, f(n)= f(n-1) + 22