Answer:
B. -9a+2
Step-by-step explanation:
You are given the sequence
[tex]t_1=2a,\\ \\t_2=3a-1,\dots\\ \\t_n=2t_{n-1}-3t_{n-2}+1,\ n\ge 3[/tex]
According to the given rule, find [tex]t_3,\ n=3[/tex]
[tex]t_3=2t_2-3t_1+1=2\cdot (3a-1)-3\cdot 2a+1=6a-2-6a+1=-1[/tex]
and [tex]t_4,\ n=4[/tex]
[tex]t_4=2t_3-3t_2+1=2\cdot (-1)-3(3a-1)+1=-2-9a+3+1=-9a+2[/tex]
