A company makes pens. They sell each pen for $9. Their revenue is represented by R = 9 x. The cost to make the pens is $1 each with a one time start up cost of $4500. Their cost is represented by C = 1 x + 4500. a) Find the profit, P, (P = R - C) when the company sells 1000 pens. 3500 9000 O 13500 O-3500 O-9000 b) Find the number of pens they need to sell to break even (when R = C). 500 643 563 4500