3-5Example 2

1. Write the prime factorization of each denominator.

9

3 3

12

3 4

× 2 2

× ×

3-5Example 2

2. Identify all common prime factors.

9 = 3 ● 3

12 = 2 ● 3 ● 3

3-5Example 2

3. Find the product of the prime factors using each common prime factor once and any remaining factors.

The LCD is 2 ● 2 ● 3 ● 3 = 36.

3-5Example 2

4. Rename each fraction using 36 as the denominator.

3-5Example 2

5. Add the like fractions.

3-5Example 2

6. Write the answer in simplest form.