What is the lowest common denominator of 15 over 57?
456
The Least Common Denominator of 57 and 35 is 1.
The LCD of 5/7 and 7/10 is 70.
57
7/15 = 28/60 19/20 = 57/60
57
The LCD for 19 and 3 is 57
It is 40,470.
3
4389
There is no highest common multiple. Once you get a common multiple - for example, multiplying 18 x 57, or using prime factorization to get the smallest common multiple - you can multiply it by 2, by 3, by 4, etc. and get ever-larger common multiples.
The GCF is 3.