The attachment at bottom is a pdf of the Review Problems for Midterm 1 over Chapters 7, 8.2-4, App. E from Martin Gay's Algebra, a combined approach.
YOU DO NOT HAVE TO KNOW HOW TO DO #18 and #20. PROBLEMS LIKE THESE ARE IN THE BOOK BUT NOT IN THE HW, QUIZZES OR TESTS.
Below are the full Video Solutions, showing what problems are worked on each video. After you do all the problems on your own, you may use the video solutions to check your answers.
1-3: http://www.youtube.com/watch?v=FN1HPtHfT4w
4-6: http://www.youtube.com/watch?v=341SFVHVmnI
7-8: http://www.youtube.com/watch?v=rtasFLfitDo
9: http://www.youtube.com/watch?v=HUyLB11-lX8
10: http://www.youtube.com/watch?v=UyAz2HODk4c
11: http://www.youtube.com/watch?v=EK9ZSvMw-Tg
12-15: http://www.youtube.com/watch?v=_e5biZpmxuk
16-17: http://www.youtube.com/watch?v=qaYNVE1FQK8
18: http://www.youtube.com/watch?v=5Yhr3-TFse0