Free LCM Calculator determines the least common multiple (LCM) between 9 and 21 the smallest integer that is 63 that is divisible by both numbers. Least Common Multiple (LCM) of 9 and 21 is 63.
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Prime Factorization of 21.
3 21
7 7
1
1. It must be divisible by 2 and 3. It IS divisible by 2. it IS divisible by 3. No remainder.
2. Add the digits and see if the sum is divisible by 3. Apply this rule to both numbers. 3 is not a common factor.
3a. 639
3b. 1035
3c. 179
answer with an example is attached below
The answer is D. 3 and 17.
3 + 17 = 20. They have a sum of 20.
17 - 3 = 14. They also have a difference of 14.
Hope I helped!
