# In this Section:

In this section, we learn how to find the LCD or least common denominator for a group of rational expressions. In pre-algebra we learned that the LCD for a group
of fractions is the smallest number that is divisible by all denominators. To find the LCD for a group of rational expressions, we use a similar technique. We begin by factoring all denominators
completely. We then list each different denominator factor. When a factor occurs in more than one factorization, we list the largest number of repeats among all factorizations.