You need at least two fractions to find something in common.
The least common denominator (LCD) is 1.
The answer is 15.
LCD(10, 15) = 30
LCM(15, 5, 8) = 120
30
120
210
120
LCD(15, 7, 8) = 840.
The LCD of x, 5, 7, 15 is 105x.
LCD(8, 15) = 120
15
LCD(5, 15) = 15
15
LCD is 24
360
120
15
15
The LCD of 13, 14 and 15 is 2730 The LCD of 1/3, 1/4 and 1/5 is 60