It is: 28
28
LCD(9, 28) = 252
LCD(28, 52) = 364
LCD(5, 14) = 70
28
LCD is y E
LCD(7, 4) = 28
28 in this case.
14
The least common denominator is 14. Whenever there are two values, and one is a multiple of the other, the multiple (larger number) is the LCD.
As 14 and 5 have no common factor other than 1, lcd of 14 and 5 is 14 × 5 = 70.