Chapter 2 - Reasoning and Proof - 2-1 Patterns and Inductive Reasoning - Practice and Problem-Solving Exercises - Page 85: 11

3, 0

Subtract 3 to get the next term. $\underset{-3}{\underset\Rightarrow{15}}, \underset{-3}{\underset\Rightarrow{12}},\underset{-3}{\underset\Rightarrow{9}}, \underset{-3}{\underset\Rightarrow{6}},\underset{-3}{\underset\Rightarrow{3}}, 0$, . . .