Answer
$y=-\dfrac{1}{3}x-2$
Work Step by Step
The given graph has a $y$-intercept of $-2$ and passes through the points $(0,-2)$ and $(-6,0).$
With the given points,
\begin{align*}
y_1&=
-2
,\\y_2&=
0
,\\x_1&=
0
,\text{ and }\\ x_2&=
-6
.\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{-2-0}{0-(-6)}
\\\\&=
\dfrac{-2-0}{0+6}
\\\\&=
\dfrac{-2}{6}
\\\\&=
-\dfrac{1}{3}
.\end{align*}
With a slope of $-\dfrac{1}{3}$ and a $y$-intercept of $-2$, by the Slope-Intercept Form of linear equations ($y=mx+b$), then the equation of the line is
\begin{align*}
y=-\dfrac{1}{3}x-2
.\end{align*}
