To find the Least Common Multiple (LCM) of 7 and 9, we can use the prime factorization method or simply multiply the two numbers since they are both prime to each other (and share no common factors other than 1).
The LCM can be calculated using the formula: \[ \text{LCM}(a, b) = \frac{a \times b}{\text{GCD}(a, b)} \] In this case, since 7 and 9 are coprime (GCD is 1):
\[ \text{LCM}(7, 9) = \frac{7 \times 9}{1} = 63 \]
Hence, the LCM of 7 and 9 is 63.