In this video, Salman Khan of Khan Academy explains linear equations. Part 2 of 4.
Khan Academy

In this video, Salman Khan of Khan Academy explains linear equations. Part 1 of 4.
Khan Academy

A helpful scientific calculator that runs in your web browser window.
Holt Online Learning

In this video, Salman Khan of Khan Academy explains linear equations. Part 4 of 4.
Khan Academy

In this video, Salman Khan of Khan Academy explains linear equations. Part 3 of 4.
Khan Academy

The site gives a small applet exploring the relationship between circles centered at the origin, linear equations, and pythagorean triples.
Pythagorean Triples

Gives a detailed explanation of how to use interval notation, followed by numerous examples, from very simple to quite complex.
Connexions

This site provides graphing tools. The GCalc 3 menu has several options for graphing. One nice aspect of this site is that multiple functions can be graphed in different colors on the same screen. Another useful feature is that it is easy to copy and paste or print the graphs that are generated.
GCalc  Java Online Graphing Calculator

A Quiz on Coordinates and Lines
SOS Math
