NutshellMath offers explanations to the problems in your textbook, in addition to more general overviews of important math topics - suitable for students using any textbook. Following are some sample explanations for you to view.
Augmented Matrices
Completing the Square and Quadratic Equations
Compound Probability
Conics
Evaluating Trigonometric Functions of General Angles
Inverse Matrices
Multiplying Matrices
Natural Logarithms
Properties of Logarithms
Rational Functions and Their Graphs
Solving Radical Equations
Solving Systems of Equations Algebraically
Trigonometric Identities