what is the least common multiple of 5 and 9?

# Explanation: ## Step1: Check if the numbers are co - prime 5 and 9 have no common factors other than 1. ## Step2: Use the co - prime LCM rule For two co - prime numbers \(a\) and \(b\), the LCM is \(a\times b\). Here \(a = 5\) and \(b=9\), so \(LCM(5,9)=5\times9\). ## Step3: Calculate the product \(5\times9 = 45\). # Answer: 45