Answer: 1/2
=================================================
Step-by-step explanation:
Your teacher wants you to find the slope
m = slope
m = (y2-y1)/(x2-x1)
m = (-1-2)/(3-9)
m = -3/(-6)
m = 1/2
----------------
Extra info:
We can think of the slope as
slope = rise/run
and furthermore,
- rise = change in y = y2-y1
- run = change in x = x2-x1
Essentially we subtract the corresponding y coordinates together, subtract the x together (in the same order as the y values), then divide the differences.