Add the problem of Exercise 1.7.

Included is the following file:

	Exercise_1.7.tm

Thank you!
							Lawrence X. Amlord
							  Oct 24th, 2013
							  Xi'an, China
Add my answer to Exercise 1.8.

Included are the following 2 files:

	Exercise_1.8.pdf
	Exercise_1.8.tm

Thank you!
							Lawrence X. Amlord
							  Oct 25th, 2013
							  Xi'an, China