The slope is
.
(Please comment if you want explanation)
Ok, My answer is marked wrong and I don't know why. Ok, kindakait asked for the slope of the line in the graph.
To find the slope of the line is
or so they call
.
We can clearly see that to be at (-2,1) from (-4,5). You have to rise by -4 units and run by 2 units. Therefor:
.
If you are not satisfied yet. Let's try another points. (0,-3) and (1,-5) and this is obvious by just eyeballing it.
.