Fill in each blank with the appropriate response.
$$
\begin{array}{c}
\quad \quad\quad\quad\quad x+3 \\
x - 1 )\overline{ x ^ { 2 } + 2 x + 3 } \\
x^{2}-x \\\hline \quad\quad\quad\quad{3 x}+3 \\
\quad\quad\quad\quad 3 x-3\\ \hline \quad\quad\quad\quad\quad\quad{6}
\end{array}
$$
can be written $x^{2}+2 x+3=$ $(x-1)$ (____) + _____