Solutions by everydaycalculation.com

The LCM of 21 and 84 is 84.

- Find the prime factorization of 21

21 = 3 × 7 - Find the prime factorization of 84

84 = 2 × 2 × 3 × 7 - Multiply each factor the greater number of times it occurs in steps i) or ii) above to find the LCM:

LCM = 2 × 2 × 3 × 7 - LCM =
**84**

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Find least common multiple (LCM) of: 42 & 168 63 & 252 7 & 28 105 & 420 147 & 588 3 & 12 42 & 84 21 & 168 63 & 84 21 & 252 105 & 84 21 & 420 147 & 84 21 & 588

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