Answer:
When the slope is undefined, it means that all points on the line have the same x-coordinate which means its an vertical line.
ex/.
If the 2 coordinates to find slope are (9,8) and (9,7)
the slope is undefined because
[tex]\frac{7-8}{9-9}[/tex]=
-1/0
you can't divide by 0
So the slope is undefined
