What is the lcm of 7 and 9?

The lcm (least common multiple) of 7 and 9 is 63. This means that 63 is the smallest positive integer that is a multiple of both 7 and 9. The process to find the lcm involves finding the prime factorization of each number, identifying the common prime factors, and multiplying those common factors together with any remaining factors from either number. In this case, the prime factorization of 7 is simply 7, while the prime factorization of 9 is 3 x 3. The only common factor is 3, so we multiply 3 x 7 x 3 to get 63.