#### Answer

$2x+y=5$

#### Work Step by Step

$\bf{\text{Solution Outline:}}$
Use the different forms of linear equations to find the equation of the line with the following given characteristcs:
\begin{array}{l}\require{cancel}
\text{through } (1,3)
\\\text{m}=-2
.\end{array}
Use the properties of equality to express the equation in the standard form.
$\bf{\text{Solution Details:}}$
Let $x_1=1,$ $y_1=3,$ and $m=-2.$
Using $y-y_1=m(x-x_1)$ or the Point-Slope Form of linear equations, the equation of the line with the given conditions is
\begin{array}{l}\require{cancel}
y-3=-2(x-1)
.\end{array}
Using the Distributive Property and the properties of equality, in the form $ax+by=c$ or the Standard Form, the equation above is equivalent to
\begin{array}{l}\require{cancel}
y-3=-2(x)-2(-1)
\\\\
y-3=-2x+2
\\\\
2x+y=2+3
\\\\
2x+y=5
.\end{array}