National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: A Quadratic Inequality
"Dr. Math" responds to a student question about writing solutions to quadratic inequalities in interval form.
Help Algebra
Help algebra.com: Polynomial and Rational Inequalities
Learn to solve inequalities and how to graph their solutions on a number line. The examples contain quadratics and rational expressions.
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.