Answer:
m = -3/4
Step-by-step explanation:
Let's look at how much x and y change as we move from A to B:
x increases by 6, from -3 to 3, and y increases by 8, from 7 to 15. Thus, the slope, m, is rise / run, or (change in y): m = 8/6 = 4/3.
Now any line perpendicular to AB has a slope which is the negative reciprocal of this 4/3: m = -3/4