Question

Enter the slope of the line through the points (4 , 15) and (4 , 12)​

Answer 1

Well, first of all, the formula to calculate slope is: M = (Yb - Ya) / (Xb - Xa)
M = (12 - 15) / (4 - 4)
M = -3/0
So, the slope of this line is: M = -3/0

Answer 2

Explanation:

slope m= (y2-y1) / (x2-x1) = 15-12 / 4-4 = 3/0 is undefined since we can not divide by 0

slope is undefined so the line is vertical