1) Explain the following concepts using the concept of consumer and producer surplus:

• Efficiency of Markets
• Costs of taxation
• Benefits of international trade

Using the concept of consumer and producer surplus

2) How might externalities may prevent market equilibrium and the various governments policies used to remedy the inefficiencies in markets caused by externalities

3) Analyze the difference between the efficiency of a tax system and the equity of a tax system as it refers to the costs imposed on taxpayers using the benefits principles. 

How can I summarize

Need some starting points, examples, and explanation, sources to point me in the right direction to understand.