The common denominator of any two or more whole numbers will always be 1.
36
There is none because the Least Common Denominator (or LCD) is the Least Common Multiple (LCM) of the denominators of a pair of fractions.
70
50
28
The Least Common Denominator (or LCD) is the Least Common Multiple (LCM) of the denominators of a pair of fractions. I assume the 7 and 21 are the denominators of two fractions you need to add or subtract.LCD(7, 21) = 21.
Only 1.
The greatest common denominator of any set of denominators is infinite.
Common multiples and common denominators can be found using the same process. They differ in their function. Common denominators are common multiples that are functioning as denominators.
The common factors of the denominators are 1 and 3, which won't help you. The least common denominator is 54, which will.
8/9, 5/12, 6/7
They are not fractions, so they do not have denominators.