Varsity Tutors
Varsity Tutors: Hotmath: Practice Problems: Solving Linear Systems by Substitution
Twenty-seven problems present a variety of practice solving linear systems by substitution. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the problem then click the "View...
Khan Academy
Khan Academy: Testing Solutions to Equations
Practice plugging in values to equations and checking to see if the equations hold true. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Purple Math
Purplemath: Solving Inequalities: An Overview
A discussion on how to solve linear and nonlinear inequalities is presented. Both the Test Method and the Factor Method of checking positive/negative intervals are included as part of the discussion.
BBC
Bbc: Algebra Revision Bite Solving Equations
BBC Schools offers a test review ("revision") of several aspects of solving equations. Content includes solving simple equations, solving equations with brackets, simplifying letters in equations, plus much more. After working through...
Purple Math
Purplemath: Solving Linear Inequalities: Introduction and Formatting
This resource demonstrates how to solve linear inequalities step-by-step and shows four different solution formats/notations viz. inequality notation, set notation, interval notation, and the last "notation" which is more of an...
Khan Academy
Khan Academy: Testing Solutions to Inequalities
Practice plugging in values to inequalities and checking to see if the inequalities hold true. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
National Council of Teachers of Mathematics
The Math Forum: Nctm: Ask Dr. Math: Solving Inequalities
In response to a student question about solving an inequality, "Dr. Math" provides a general discussion of what is necessary to solve these types of problems.