The answer is real numbers.
The Ruler Postulate states that on any given number line, every point can be paired with a number and every number can be paired with a point called the coordinates.
We know that on a number line, there are both positive and negative numbers.
The numbers on the right side of 0 are positive and the number on left side of 0 are negative.
So, the numbers in the coordinates of the number line are all real numbers.
i think it will be zero as slope has a formula of difference between initial and final distance divided by itz time interval