please show calculation.

Suppose the demand and supply functions for a small country are given by: Q d = 100 - 3P and Q s= - 20 + 2 P Assuming NO trade; determine equilibrium Price 100- 3P = - 20+2P Quantity Consumer Surplus Producer surplus Assuming FREE trade and a world price of $ 15, determine. Domestic production Domestic consumption Imports Change in producer surplus Assuming a $ 5 (per unit) tariff is placed on imports, determine. Domestic production Domestic consumption Imports Tariff Revenue Deadweight loss