We are asked to find the slope of the segment that joins the points (2, 7) and (2, -6) on the plane.
Notice that these two points contain the SAME x value (2). which means they are both located on the VERTICAL line that passes through x = 2. Therefore, the slope cannot be estimated (it is UNDEFINED) because the solpe formula involves a division by ZERO.
Our answer to a question like this would be:
slope = UNDEFINED.