Writing Equations of Parallel Lines

Two lines are parallel if their slopes are identical. Let's recall the slope-intercept form of a line. $$\begin{array}{c}y=mx+b\end{array}$$ Here, we can identify the slope as the value of $m.$ We will rewrite each equation in this form to find the slopes. Let's start with $A.$ Now we do the same thing for $B$ and $C.$

Line	Slope-intercept form	Slope
$A$	$y=\text{-}2x-1$	$\text{-}2$
B	$y=\text{-}9x+24$	$\text{-}9$
C	$y=x+4$	$1$

Now that we've identified the slope of each line, we can see that none of the lines have the same slope, so none of them are parallel.