Answer:
A) 9 => 6 => 3 => 0 => -3 => -6
B) Using Formula
[tex]a_{n}= a_{1} + d(n-1)[/tex]
=> [tex]a_{n } = 9+3(n-1)[/tex]
=> [tex]a_{n}= 9+3n-3\\a_{n} = 3n+6[/tex]
Answer: [tex]a_{n }= 3n+6[/tex]