This is free math site. You can learn
=> Operations with real number
=> Solving equations and inequalities
=> Polynomials and Exponents
=> Factoring and Solution of Quadratic Equations by Factoring
=> And much more
From the site, “…We are a group of authors who have had a long and successful career in education and publishing. We feel it is time to give something back to the educational community for its commitment to using our textbooks for over 20 years. Several million students have purchased at least one of our textbooks, but you will now be able to start using those same textbooks along with the teacher’s resource material for free…”
Visit site online.