Ducksters
Ducksters: Kids Math: Linear Equations: Slope Forms
Explore the slope-intercept and point-slope forms of linear equations and how to graph them on this webpage.
Cool Math
Coolmath: Perpendicular Lines
This CoolMath Resource will help students determine if lines are perpendicular by finding the slope, using the point-slope formula, and graphing.
Wolfram Research
Wolfram Math World: Algebra
MathWorld provides a basic overview of Algebra. Includes a few formulas and many links to related topics.