There is none because the Least Common Denominator (or LCD) is the Least Common Multiple (LCM) of the denominators of two or more fractions. Even if you converted your numbers (x) to their fraction equivalents (x/1), the LCD will always be 1.
The least common denominator (LCD) is 1.
You need at least two fractions to find a common denominator.
3
63
it's 63
126
63
63
Using the least common denominator technique: 2/7 = 18/63. 5/9 = 35/63. 18/63 + 35/63 = 53/63. Because 53 is prime, this fraction cannot be reduced further.
504 9*56 = 504 8*63 = 504
63 is their lowest common denominator, so you should use that. 2/7 = 18/63 and 4/9 = 28/63
63