This series works through practice problems based on California's Algebra I standards. It covers the core topics of a first algebra course, including simplifying expressions, graphing lines, solving inequalities, functions, and word problems. It also tackles quadratics, with videos on factoring, completing the square, and the quadratic formula. It is a helpful way to review and check your understanding before a test like the GED. It works best if you are comfortable with arithmetic and have some exposure to algebra.
Note: All Khan Academy content is available for free at www.khanacademy.org