Please explain each step

80. CONSUMERS' SURPLUS Suppose that the consumers' demand function for a certain commodity is D(9) = 50 39-0 dollars per unit. a. Find the number of units that will be bought if the market price is $32 per unit. b. Compute the consumer willingness to spend to get the number of units in part (a). c. Compute the consumers' surplus when the market price is $32 per unit. Use the graphing utility of your calculator to graph the demand curve. Interpret the consumer willingness to spend and the consumers' surplus as areas in relation to this curve