Add my answer to Exercise 2.8.

Included are the following 2 files:

	Exercise_2.8.pdf
	Exercise_2.8.tm

Thank you!
							Lawrence R. Amlord
							   May 24th, 2013
							   Xi'an, China
Update my answer to Exercise 2.8.
Add my answer to Exercise 2.9.

Included are the following 2 files:

	Exercise_2.9.pdf
	Exercise_2.9.tm

Thank you!
							Lawrence R. Amlord
							   May 24th, 2013
							   Xi'an, China