1. Warm-up: Here is an example to help you do this warm-up.

2. Homework:

3. 9.c add and subtract rational expressions After this lesson you will be able to… Find the least common denominator for two or more rational expressions Build up the fractions so that they all have the LCD Add or subtract the fractions To add or subtract fractions to simplify complex fractions

4. BIG IDEA!!! You can only add/subtract fractions with the same denominator!

5. Procedure: If the fractions have the same denominator… 1. Add/Subtract the numerators. WATCH OUT! Minus signs distribute! 1. Keep the same denominator. 2. Reduce answer if possible.

6. Example 1:

7. Example 2:

8. If the fractions don’t have the same denominators… You MUST make them have the same denominator before you can add or subtract them.

9. Building a Least Common Denominator (LCD) BIG IDEA!!! An LCD will show the factors of both denominators!

10. PROCEDURE: 1. Factor each denominator completely. 2. Multiply the top and bottom of each fraction by whatever factors are missing from that denom. 3. Rewrite as one large fraction. This will help you avoid sign errors. 4. Multiply out the numerator and then combine like terms. 5. Factor and reduce if possible.

11. Example 3:

12. Example 4:

13. Example 5:

14. Example 6:

15. Example 7:

16. Simplifying Complex Fractions Example 8:

17. Example 9:

18. Homework: HW ST 9.c both sides