Hello! :)
The slope of this line is 0.
Remember, to find the slope, we divide the rise by the run. The rise is how many units we move up; the run is how many units we move right or left.
Here, we move 0 units up, so the rise is 0.
No matter what the run is, the slope is 0 anyway.
Hope it helps you!
If you have any questions, feel free to ask! (:
~An excited gal
