Identify and explain how firms engage in international business?
Discuss the difficulties represented by using different currencies and
the tools used by international Business to overcome them?

Since it may take more than a few minutes, or even hours to correctly
research this question, I suggest that you consider increasing your
price, or reducing the complexity of your question.
You may wish to review the Google Answers pricing guidelines:

http://answers.google.com/answers/pricing.html

Nenna-GA
Google Answers Researcher