1. Adding and Subtracting Rational Expressions with Different Denominators 7.4 1.Find the LCD of two or more rational expressions. 2.Given two rational expressions, write equivalent rational expressions with their LCD. 3.Add or subtract rational expressions with different denominators.

2. Solve: LCD = 36 Clear the fractions.

3. How did we find the LCD? 2∙22∙2∙33∙3 LCD: 2 ∙ 2∙3 = 36 Take all of the first factors and then any additional factors that are not already written.

4. Find the LCD: 2∙3 2∙5 LCD: 2 ∙ 3∙ 5= 30

5. Find the LCD: LCD: For the LCD use the largest exponent of each prime factor. LCD:

6. Find the LCD: LCD: Take all of the first factors and then any additional factors that are not already written.

7. Find the LCD: LCD:

8. Find the LCD: LCD: