๐Ÿ“ˆcollege algebra review

Least common denominator

Written by the Fiveable Content Team โ€ข Last updated September 2025
Written by the Fiveable Content Team โ€ข Last updated September 2025

Definition

The least common denominator (LCD) of two or more rational expressions is the smallest positive integer that is divisible by each of their denominators. It is essential for adding, subtracting, or comparing fractions.

5 Must Know Facts For Your Next Test

  1. To find the LCD, identify the least common multiple (LCM) of the denominators.
  2. The LCD provides a common base for combining rational expressions.
  3. Factoring each denominator into its prime factors helps in determining the LCD.
  4. Using the LCD simplifies the process of solving equations involving rational expressions.
  5. The LCD is particularly useful when dealing with complex fractions.

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