Slope = (y2 -y1)/ (x2- x1)
_______________
Using the points (x, y)
Point 1 (-2,7) x1= -2 ; y1= 7
Point 2 (1,7) x2= 1 ; y2 = 7
____________________________
Replacing the points
Slope = (7 - 7)/ (1- (-2)) = 0/ 3 = 0
________________________
___________________________________
Answer
Slope =0