Find the slope of the line by using two points on the line.
Using (0,-2) and (3,0)
The slope is the change in Y over the change in x:
Slope = (0 - -2) / (3-0) = 2/3
The y intercept is where the line crosses Y at = 0, from the picture when X is 0 the line crosses at -2.
The equation becomes 2/3x -2
The answer is: f(x)=2/3x−2