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}$