What is the slope of the line through points (-3.5,-7) and (-1.5,-7)?
zero, i.e. 0
The slope of a line is defined to be the "rise" over the "run". That is, the change of elevation, which is the change in the y-coordinates, in moving from the smaller x-coordinate to the larger x-coordinate. In this case, the y-coordinates are the same, so there is no rise, i.e. the "rise" is 0. The run is 2, since the distance between -3.5 and -1,5 is 2.
So, the slope is