You have the equation, now you need two points to graph, using the intercept method, "(0,?), (?,0)"
When x is 0 (substitute x with 0 in the equation, to find y)...y = 40
When y is 0 (substitute y with 0 in the equation, to find x)...x = 0.67
You have your 2 points (0,40) and (0.67,0), now graph them and draw a line connecting the 2 points..and u have your graph!