While neither 9 nor 8 are prime numbers, the factors of 9 are 3*3 and of 8 are 2*2*2. Since they share no factors in common, their product will be the least common multiple. (Multiples of 9 are 18, 27, 36, 45, 54, 63, and 72; Multiples of 8 are 16, 24,32, 40, 48, 56, 64, and 72).
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