Question

What is the slope of the line

Answer 1

To find the slope of the line, choose any of the points in the table and set up this expression:
y2 - y1 / x2 - x1, where y2 is the y coordinate of the second point you chose, y1 is the y coordinate of the first point you chose, x2 is the x coordinate of the second point you chose, and x1 is the x coordinate of the first point you chose. 

So, 
3 - (-6) / 2 - 2 = 9 / 0 for the first two points. The slope of the line is undefined because it is a vertical line.