the graph that best represents the function in this case, will be given by evaluating x in the function sometimes to build the number of points needed to describe the straight line. In this case, the graphic is shown in the attached file
x= 0 1 2 3 4 5 6 7 8 9 10
F(x)= 6 4 2 0 -2 -4 -6 -8 -10 -12 -14
zero is at x = 3!!!