Chapter 9, Problem 2RE

In Problems 2-6, $P$ is a transition matrix for a Markov chain. Identify any absorbing states and classify the chain as regular, absorbing, or neither.

$\begin{array}{l}\begin{array}{cc}A& B\end{array}\\ P=\begin{array}{c}A\\ B\end{array}\left[\begin{array}{cc}1& 0\\ .7& .3\end{array}\right]\end{array}$