LCD stands for "least common divisor" which is actually a mistaken term because it would mean the smallest integer that evenly divides every member of a set - that's always 1 !
The two terms that are being confused in LCD are actually
> Least common multiple (LCM), the smallest number that's a multiple of all members of the set
> Greatest common factor (GCF), the largest number that evenly divides every member of the set
4, 7, and 9 do not have any factors in common, so their LCM is simply their product, 252, while their GCF is 1.
LCD(7, 9, 2) = 126.
The LCD of 3/4 and 7/9 is 36.
84
LCD(4, 9) = 36.
The LCD for 4/7 and 7/8 is 56.
LCD(7, 9, 2) = 126.
It is: 252 which is also the LCM
LCD(7,9,13) = 7*9*13 which is 819
LCD(4, 2, 9) = 36
LCD(7, 4) = 28
For 49,57: 2793 For 4/9, 5/7: 63
63
63
If you mean lcm, it is 36 because 9 x 4 equals 36 and 3 x 12 equals 36.
63
126
315