In this lesson, you will learn how to find the least common denominator (LCD) of rational expressions. The LCD is the least common multiple of the denominators, factored in the case of algebraic fractions. You can use a building-up approach or find the least common multiple of the numerical parts and each kind of factor. Factoring the denominators is the first step in finding the LCD, and then you can build it up by multiplying the missing factors. It is important to leave the LCD in factor form for ease of adding fractions.
This video shows a method for finding the least common denominator of rational expressions. I've posted at least 2 other videos with methods, explanations, and examples for finding the LCD.
More free YouTube videos by Julie Harland are organized at http://yourmathgal.com