Answer: f(x)=-0.5x
Explanation:
First we can identify that the y-intercept or b is equal to 0.
Since the line is going down from left to right it indicates that the slope is negative so A and B are not an option.
Next we can find the slope by picking two points on the line and solving using the slop formula.
However, in this problem you can count the rise/run.
Starting at 0,0 since it is a point on the line we can go down one and to the right two, since we are going down one that will be a -1 and we go to the right two meaning its positive.
This turns into -1/2 equaling -0.5x because it is the slope!