We assume you want to know what Lamar should have written as the definition of f(x).
We know the points (-3, -2) and (2, 3) are on the graph. These differ in both the x-direction and the y-direction by 5, so the slope of the line is 5/5 = 1.
Since the line goes through point (-3, -2) with slope 1, we can use the point-slope form of the equation of a line:
f(x) = 1(x -(-3)) +(-2)
f(x) = x +1 . . . . . . . . . . after simplification
