Pick two of the fractions and find the Least Common Multiple of those two denominators. Then take that number, and find the Least Common Multiple between that and the third denominator. This number will be the Least Common Denominator between the three fractions.If you don't care to find the Least common denominator, then just take the three denominators, and multiply them together.
To add three fifths and seven tenths, we need to find a common denominator. The least common multiple of 5 and 10 is 10, so we convert three fifths to six tenths. Therefore, six tenths plus seven tenths equals thirteen tenths. Thirteen tenths can be simplified to one and three tenths, or 1.3 as a decimal.
Suggestion: Find the least common multiple using your favorite method (for example, prime factorization). Then multiply that by 1, by 2, and by 3, to get your answer.
The least common multiple of 9, 36, and 60 is the smallest number that can be divided by each of the three numbers without a remainder. In this case, the answer is 180. (180/60 = 3, 180/36 = 5, and 180/9 = 20)
105
84
119
3 * 7
LCM: 42
The LCM is: 210
The LCM is: 54
420
3 * 35 = 5 * 21 = 7 * 15 = 105
The Least Common Multiple (LCM) of (54,63) is 378.
1197 21*57 = 1197 19*63 = 1197
15
12