Answer: 0
Explanation:
Slope is a value that describes the steepness and direction of a line.
A line with a negative slope, said to be decreasing, runs downwards from left to right.
A line with a positive slops, said to be increasing, runs upwards from left to right.
A horizontal line has a slope of zero because y does not change. A vertical line has an undefined slope because you cannot divide by zero (x does not change).
I hope this helps to understand :)