Math TV Free videos for quick review of key algebra concepts; some are in Spanish
Free videos from Khan Academy These videos address all the main topics of algebra and precalculus. Free registration is required.
Study Guide for Precalculus - This notebook organizer will help you develop a section-by-section summary of the key concepts in Precalculus. It is a set of templates to help you take notes, review section highlights, draw graphs, and keep track of homework assignments. From the Cengage companion web site to Larson's Precalculus, 4th ed. (but you can use it with any textbook - the page numbers and section numbers may differ, but the content will be very similar.)
Wolfram|Alpha Type in an equation to solve, or a function to graph in the dialog box for Wolfram|Alpha! Use it to explore concepts and check homework problems. For example, type solve x^2-9=0 or plot x^2-9, x=-2 to 4
Desmos A quick and easy interactive graphing app
Geogebra- free graphing program
General data graphing applet from the National Center for Education Statistics. Very cool.
Free Textbooks from OpenStax
OpenStax College Algebra Provides a comprehensive exploration of algebraic principles and meets scope and sequence requirements for a typical college algebra course.
OpenStax Algebra and Trigonometry Provides a comprehensive exploration of mathematical principles and meets scope and sequence requirements for a typical introductory algebra and trigonometry course.
OpenStax PreCalculus Provides a comprehensive exploration of mathematical principles and meets scope and sequence requirements for a typical precalculus course.