Beginning Algebra With Applications, Chapter 5, 5.4, Section 5.4, Problem 20

Using the point slope formula, find the equation of the line that passes through the point whose coordinates are $(2,3)$ and has slope of $-1$


$
\begin{equation}
\begin{aligned}

(x_1, y_1) =& (2,3)
&& \text{Let $(x_1, y_1)$ be the given point}
\\
m =& -1
&& \text{$m$ is the given slope}
\\
y - y_1 =& m(x- x_1)
&& \text{Point slope formula}
\\
y - 3 =& -1(x-2)
&& \text{Substitute $2$ for $x$, 3 for $y$ and $-1$ for $m$}
\\
y - 3 =& -x+2
&& \text{Rewrite the equation in the form } y = mx+b
\\
y =& -x+5
&& \text{Add $3$}

\end{aligned}
\end{equation}
$