Respuesta :

Answer: D

Explanation:

When you use the slope formula the result is impossible to use.

[tex]\frac{y_{2} -y_{1} }{x_{2}-x_{1} }[/tex]= [tex]\frac{-9+9}{-9+3}[/tex]=[tex]\frac{0}{-6}[/tex]=undefined

Answer: Undefined

Explanation:  Because both slopes are vertically parallel, meaning they will never intercept.