Here are some websites that I hope will help you some are reviews others are to help you practice with further questions.

http://www.wtamu.edu/academic/anns/mps/math/mathlab/beg_algebra/beg_alg_tut18_ineq.htm

http://www.purplemath.com/modules/syslneq.htm

http://www.analyzemath.com/Linear_Inequalities/Linear_Inequalities_Tutor.html

https://www.youtube.com/watch?v=6oehycq06vo

https://www.youtube.com/watch?v=0VVQYOMRlkQ

http://www.morris.umn.edu/~pehng/Ma3401/han3.pdf

http://people.richland.edu/james/ictcm/2006/

http://en.wikibooks.org/wiki/Applicable_Mathematics/Linear_Programming_and_Graphical_Solutions

http://commons.wikimedia.org/wiki/File:Linopt-feasible-region.png

http://people.richland.edu/james/ictcm/2006/slopeobjective.html