There is none because Least Common Denominator (or LCD) refers to the Least Common Multiple (LCM) of the denominators of two or more fractions or mixed numbers. Even if you converted your whole numbers (x) to their fraction equivalents (x/1), the LCD would always be 1.
If those numbers are denominators, the lowest common denominator is 420.
It is: 84
The lowest common denominator of any set of whole numbers is 1
84
84
84
LCD(6, 7, 12) =84
LCM(12, 14) = 84
1260.
It is: 3780
It is: 1680
A common denominator is 84.
A common denominator is 84.