ANSWER
f(x) = -4x - 2
Step-by-step explanation
The slope-intercept form of the equation of a line is:

Where m is the slope and b is the y-intercept.
The first thing we can get from the graph is the y-intercept - which is the point where the line crosses the y-axis:
The y-intercept is -2.
To find the slope we can select another point on the line and use the formula:

The slope is:

So the equation of the line is:
