Can you teach me this homework?

2. Suppose a particular product in a particular market has 100 buyers and 40 sellers. Each buyer's demand function is identical as qa = 20 - 2P and so is each seller's supply as qs = 20p - 25, where qa denotes each buyer's quantity demanded, qs denotes each seller's supplied and P denotes the price (baht per unit). (a) Derive the market demand QD and market supply (Qs) functions. Calculate the equilibrium price (P*) and equilibrium quantity (Q*). (b) Draw the figure of demand and supply. Be sure to use quantity on the horizontal axis and price on the vertical axis. After drawing the figure, calculate the consumer's surplus and producer's surplus and indicate the areas that show consumer's surplus and producer's surplus