456
What is the lowest common denominator of 15 over 57?
The Least Common Denominator of 57 and 35 is 1.
The LCD of 5/7 and 7/10 is 70.
The common denominator is usually the Lowest (or Least) Common Multiple of the numbers involved. Where two numbers have no common factors then the LCM is simply the product of those numbers. As 19 is a prime number and has no factors in common with 18 then the common denominator is 18 x 19 = 342.
57
First, convert 2 3/8 into eighths. This gives you 19/8. Then multiply 19/8 X 2/3. This gives you 57/24 times 2/3 (or when finding the common denominator, yields 38/24, or 19/12 when reduced to the lowest denominator possible).
The least common multiple of 57 , 24 = 456
It is 40,470.
3
The LCD for 19 and 3 is 57
4389
The greatest common factor of 24 and 57 is 3.