(7, -1) 2. What is the slope of a line that is perpendicular to the line joining point A (9, 9)? and point B

Step-by-step explanation:

Given the point A (9, 9) and B(7, -1)

The slope of the line AB is expressed as:

slope = Δy/Δx

slope = y2-y1/x2-x1

slope = -1-9/7-9

slope = -10/-2

slope = 5

For two lines to be perpendicular, the product of their slope must be -1

mM = -1

M is the slope of the line perpendicular to AB

Substitute m = 5 into the equation

5M = -1

M = -1/5

Hence the  slope of a line that is perpendicular to the line joining point A and B is -1/5