Interactive Mathematics
Interactive Mathematics: Solving Equations
The steps to solving one-variable equations are demonstrated in several examples, which include variables on both sides of the equations and parentheses.
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.
Purple Math
Purplemath: Systems of Linear Inequalities
This Purplemath lesson describes how to solve a system of linear inequalities by graphing.
Interactive Mathematics
Interactive Mathematics: Graphical Solution of Non Linear Systems
Using the graphing method, several systems of nonlinear equations are solved. Follow each example step by step to see how solutions are derived.
Math Medics
S.o.s. Math: Systems of Equations in Three Variables
It is often desirable or even necessary to use more than one variable to model a situation in many fields. When this is the case, we write and solve a system of equations in order to answer questions about the situation.