Answer
$y=-4$
Work Step by Step
Let $(x_{1},y_{1})=(2,-4)$ and $(x_{2},y_{2})=(0,-4)$
Slope $m=\frac{y_{2}-y_{1}}{x_{2}-x_{1}}=\frac{-4-(-4)}{0-2}=\frac{0}{-2}=0$
Because the line crosses the y-axis at $(0,-4)$,
Y-intercept $b=-4$.
Slope-intercept form is
$y=mx+b$.
Substituting the values of $m$ and $b$, we get an equation of line as
$y=0x-4$ or $y=-4$
