The rental rate for a cement mixer has a flat rate of $40 plus $20 for each day of the rental. The graph shows points representing the total cost of the rental.
Which linear equation, in slope-intercept form, that models the total cost of the rental over time?
A.y = 20x +40
B.y = 25x
C.y = x + 50
D.y = 75x
E.y = 50x + 25