3
The least common denominator (LCD) is 1.
You need at least two fractions to find a common denominator.
63
it's 63
126
63
63
504 9*56 = 504 8*63 = 504
63
63
Well, honey, the least common denominator for 7 and 9 is 63. You gotta find the smallest number that both 7 and 9 can divide into evenly, and that's 63. So there you have it, 63 is the magic number for those two divas.
The greatest common denominator of 63, 72 and 24 is 3.