In this video, Salman Khan of Khan Academy explains systems of equations.
Khan Academy

In this Early Edge video lesson, you'll learn more about Working with Inequalities, so you can be successful when you take on highschool Math & Algebra.
The Princeton Review

This video includes sample exercises and stepbystep explanations of absolute value equations and systems of equations for the California Standards Test.
Khan Academy

In this Early Edge video lesson, you'll learn more about Graphing Inequalities, so you can be successful when you take on highschool Math & Algebra.
The Princeton Review

Excellent site showing examples of algebra, trig, calculus, differential equations, and linear algebra.
Paul's Online Math Notes

Need help solving systems of linear equations? In this video, a Tutor.com algebra tutor uses the substitution method to solve a system of linear equations, and shows you how to use graphing to make sure you don’t get tricked by systems of parallel lines that have no solution. You’ll graph the linear equations, find their point of intersection, solve them using substitution, and check your work to make sure it all makes sense.
Tutor.com

Explains the difference between inconsistent, dependent and independent systems.
algebra.com
