Answer:
45
Explanation:
The LCD is the least common denominator.
The least common denominator is the least common multiple of the denominators.
To find the least common multiple of numbers do this:
1. Find the prime factorizations of the numbers.
9 = 3^2
15 = 3 * 5
2. The LCM is the product of the factors that are common and not common with the larger exponent.
Both numbers have 3 as a factor, so 3 is a common factor. Choose the one with the larger exponent. The prime factors include 3 and 3^2. Chose the one with the larger exponent: 3^2.
5 is also a factor. It is not common because only 15 has it, but choose it anyway.
LCM = 3^2 * 5 = 9 * 5 = 45
LCD = 45