###### Item b

On the plot below, graph the lines

\begin{equation*}
\begin{aligned}
y \amp = x+1 \\
y \amp = x-1\text{.} \\
\end{aligned}
\end{equation*}

At what point or points \((x,y)\text{,}\) do the lines intersect? How many points \((x,y)\) satisfy both equations?