here is a rule for a sequence. After the first two terms, each term is half the sum of the previous two terms.

Answer:
Step-by-step explanation:
A)
(22+12)/2 = [17] (12+17)/2 = [14.5] (17+14.5)/2 = [15.75]
B)
(10.5*2) - 5 = [16] ......... NOT 13