We have to complete a table with some points (x,y) from the line that is represented in the graph.
To do that we choose a value of x and wee which value of y corresponds to that value of x in the line.
For example, we can do it for x = 1 as:
Then, we have one point for the table: when x = 1, y = -9.
We can repeat this process for some points of x:
x | y
-------------
-4 | 1
-3 | -1
-2 | -3
-1 | -5
0 | -7
1 | -9
2 | -11
We can see that for each unit increase in x, the value of y decreases by 2. This indicates that the slope is m = -2.
Also, for x = 0, y = -7. Then b = -7 is the y-intercept.