Uses slopes to determine whether the opposite sides of quadrilateral WXYZ are parallel.

the sides of the quadrilateral WXYZ are NOT parallel
Explanation
two segments are parallel if the slope is the same .so
the slope of a line ( or segment) is given by
[tex]\begin{gathered} \text{slope}=\frac{\Delta y}{\Delta x}=\frac{y_2-y_1}{x_2-x_1} \\ \text{where} \\ P1(x_1,y_1)\text{ is the initial point} \\ \text{and} \\ P2(x_2,y_2)\text{ is the endpoint} \end{gathered}[/tex]Step 1
so, let's find the slopes of the sides
a)WX
let
W=P1(-1,-1)
X=P2(-3,-1)
now, replace in the formula
[tex]\begin{gathered} \text{slope}=\frac{y_2-y_1}{x_2-x_1} \\ slope_{_{WX}}=\frac{-1-(-1)}{-3-(-1)}=\frac{-1+1}{-2}=\frac{0}{-2}=0 \\ slope_{_{WX}}=0 \end{gathered}[/tex]b)XY
let
X=P1(-3,-1)
Y=P2(-2,4)
now, replace in the formula
[tex]\begin{gathered} \text{slope}=\frac{y_2-y_1}{x_2-x_1} \\ slope_{_{XY}}=\frac{4-(-1)}{-2-(-3)}=\frac{5}{1}=5 \\ slope_{_{XY}}=0 \end{gathered}[/tex]c)YZ
let
Y=P1(-2,4)
Z=P2(2,3)
now, replace in the formula
[tex]\begin{gathered} \text{slope}=\frac{y_2-y_1}{x_2-x_1} \\ slope_{_{YZ}}=\frac{3-4}{2-(-2)}=\frac{-1}{2+2} \\ slope_{_{YZ}}=-\frac{1}{4} \end{gathered}[/tex]d)ZW
let
Z=P1(2,3)
W=P2(-1,-1)
now, replace in the formula
[tex]\begin{gathered} \text{slope}=\frac{y_2-y_1}{x_2-x_1} \\ slope_{_{Zw}}=\frac{-1-3}{-1-2}=\frac{-4}{-3}=\frac{4}{3} \\ slope_{_{ZW}}=\frac{4}{3} \end{gathered}[/tex]conclusion: two lines ( or segments are parellale if the slope is the same), here we found that the 4 slopes are differentes, so the sides of the quadrilateral WXYZ are NOT parallel
I hope this helps you