The answer is their product. The least common multiple (LCM) is the smallest number which is a multiple of two numbers. If two numbers have no common factors greater than 1, then their LCM will be their product. For example, take numbers 7 and 9. They have none common factor greater than 1. So, LCM will be 7 * 9 = 63. Hope this helps. Let me know if you need additional help!