Recognizing Arithmetic Sequences

To describe the pattern of the sequence, we need to find the change that occurs between each consecutive term. Here, notice that the difference between each pair of consecutive terms in the sequence is $\text{subtracting}$ $6.$ We can describe the pattern as the previous term subtracted $6.$ $$\begin{array}{r}10\stackrel{-6}{\to }4\stackrel{-6}{\to }\text{-}2\stackrel{-6}{\to }\text{-}8\end{array}$$ To find the fifth and sixth terms, we have to subtract $6$ twice. $$\begin{array}{r}10\stackrel{-6}{\to }4\stackrel{-6}{\to }\text{-}2\stackrel{-6}{\to }\text{-}8\stackrel{-6}{\to }\text{-}14\stackrel{-6}{\to }\text{-}20\end{array}$$