Suppose the supply curve for mobile phones can be expressed as P = 100 + 20 and the demand curve for mobile phones can be expressed as P = 1,000 3Q where P is the price of mobile phones and Q is the quantity of mobile phones. (a) Show how to solve for equilibrium quantity Q" and price P" of mobile phones, total expenditure paid by consumers on mobile phones TE", and total revenue mobile phone producers receive in equilibrium TR". (b) Suppose the government considers mobile phones as undesirable product in the society and imposes a per unit tax of $40 on mobile phone producers. Demonstrate how to compute the quantity purchased (3', the price the consumers pay PC, the price the producers keep Pp: total expenditure paid by consumers on mobile phones TE\