SoundsGreat manufactures and sells earbuds. They sell their earbuds for $40 per unit. The manufacturing costs consist of a fixed cost of $4050 and a production cost of $15 per unit. 

(a) Write the cost and revenue equations.

(b) Graph both equations for up to and including 200 units on the same axes.

(c)  Use the graph to estimate the number of units SoundsGreat must sell to break even. 

(d) Write the profit formula.

(e) Use the profit formula to determine whether SoundsGreat makes a profit or loss if 155 units are sold.

(f)  How many units must SoundsGreat sell in order to make a profit of $575?

Part of the question involves determining a system of equations that models the situation.