Oswego City School District
Regents Exam Prep Center: Adding and Subtracting Fractions
Use this site to learn how to add and subtract algebraic fractions, even if there aren't common denominators. Provides plenty of examples.
Oswego City School District
Regents Exam Prep Center: Simplifying (Or Reducing) Fractions
At this site from the Oswego City School District, you can learn how to simplify fraction (rational expression) that contain monomials or higher degree polynomials. Reducing fractions is made easier with help from this page.
Help Algebra
Help algebra.com: Simplifying Rational Expressions
The process of factoring and canceling is used to simplify, multiply, and divide rational expressions. Adding and subtracting rational expressions is also demonstrated, including finding common denominators.