Solutions by everydaycalculation.com

The lcm of 3 and 21 is 21.

- Find the prime factorization of 3

3 = 3 - Find the prime factorization of 21

21 = 3 × 7 - Multiply each factor the greater number of times it occurs in steps i) or ii) above to find the LCM:

LCM = 3 × 7 - LCM =
**21**

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Find least common multiple (lcm) of: 6 & 42 9 & 63 1 & 7 15 & 105 21 & 147 6 & 21 3 & 42 9 & 21 3 & 63 15 & 21 3 & 105 21 & 21 3 & 147

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