Identical Sequences - Definition & Examples

We have two arithmetic sequences: sequence $A$ and sequence $B$. $$\begin{align} \text{Sequence }A:& \begin{cases} a_3=9\\ a_4=12\\ a_5=15 \end{cases}\\ \\ \text{Sequence }B:& \begin{cases} b_7=26\\ b_8=29\\ b_9=32 \end{cases} \end{align}$$