The least common denominator (LCD) is the smallest number that can be a common denominator for a set of fractions. It's also known as the lowest common denominator.
The denominators of two fractions are given as:
Factoring the first expression:
It's clear there is no common factor between both denominators. Such expressions and numbers are called to be coprime.
For example, 9 and 25 are coprime, but they are not prime numbers individually.
When two numbers or expressions are coprime, the LCD is just their product.
Therefore the Least Common Denominator is:
