Answer
$x-y=-1$
Work Step by Step
With the given points, $(2,3)\text{ and } (4,5),$ then
\begin{align*}
y_1&=
3
,\\y_2&=
5
,\\x_1&=
2
,\text{ and }\\ x_2&=
4
.\end{align*}
Using $m=\dfrac{y_1-y_2}{x_1-x_2}$ or the Slope Formula, the slope, $m,$ of the line is
\begin{align*}
m&=\dfrac{3-5}{2-4}
\\\\&=
\dfrac{-2}{-2}
\\\\&=
1
.\end{align*}
Using $
y-y_1=m(x-x_1)
$ or the Point-Slope Form of linear equations, with the point $(2,3)$ and $m=1,$ then
\begin{align*}
y-3&=1(x-2)
.\end{align*}
Using the properties of equality, in the form $ax+by=c$ or the Standard Form of linear equations, the equation above is equivalent to
\begin{align*}
y-3&=x-2
\\
-x+y-3&=x-2-x
\\
-x+y-3&=-2
\\
-x+y-3+3&=-2+3
\\
-x+y&=1
\\
-1(-x+y)&=(1)(-1)
\\
x-y&=-1
.\end{align*}
