Answer:
The slope is -2
Step-by-step explanation:
The slope can be calculated as

Where (x1, y1) and (x2, y2) are the coordinates of two points in the line.
Replacing (x1, y1) by ( 0, -1) and (x2, y2) by (1, -3), we get:

Now, we can check the answer using the following drawing
Since rise over run is also equal to 2/(-1) = -2. We can say that the slope is -2.