21
LCD(6, 8) = 24
LCD(7,9,13) = 7*9*13 which is 819
The factors of 42 are 1, 2, 3, 6, 7, 14, 21 and 42. The factor pairs of 42 are 1 x 42, 2 x 21, 3 x 14, and 6 x 7.1, 2, 3, 6, 7, 14, 21, 42.1 2 3 6 7 21 14 42
The LCD of x, 5, 7, 15 is 105x.
The LCD of 6 and 7 is 42
21
21.
LCD(8, 21, 7) = 168.
Put as 6/7 - 4/21, change to LCD: 18/21 - 4/21, which is 14/21, or 2/3
LCD is 24
21
The LCD of 6, 5, and 7 is 210.
126
42 is the least common denominator for 21 and 6
126
It is 42