Algebra.com is an online homework helper comprises of free math tutors, solvers, and lessons. There are five sections of math concepts available such as Pre-algebra, Algebra I, Algebra II, Geometry, and Physics each has hundreds of solved problems. Lessons and solvers are submitted by contributors of the site.
You can ask any questions on question board in order to clarify your doubts. Registration is must if you want to access full history you have accessed and for accessing other features you need to create an account.