http://www.greenemath.com/
In this lesson, we will learn how to add and subtract rational expressions. For this process, we will first need to find the LCD for a group of rational expressions. Once this is done, we can convert each rational expression into an equivalent rational expression with the LCD as its denominator. From there, we will perform the operations with the numerator and place the result over the denominator. Our last step is to simplify our rational expression and report our answer.