The slope intercept form is:

Where
m is slope
b is y-intercept (y-axis cutting point)
Let's find the slope (m) using the 2 points given. The formula is:

Let's put the points (0,2) and (2,-4) and find the slope:

The y intercept, y axis cutting point, is directly taken from the graph as "2".
Thus, now we can write:
