A coffee shop has fixed monthly expenses of $2,000 and a variable cost of $2 per cup of coffee sold. The revenue is $0 when 0 cups are sold and $0 when 400 cups are sold due to capacity limits. The maximum revenue occurs when 200 cups are sold. Which system of equations represents the linear cost function C(x) and the quadratic revenue function R(x) , where x represents the number of cups of coffee sold?