1. Warm-Up 8/20/12 Add or Subtract the following: 1) 2) Answers: Homework: HW P6C (#41-53 odds)

2. Homework Answers: Pg. 77, 33-40

3. Find the Least Common Denominator and Combining Terms 1.Factor each denominator completely. 2.List the factors of the first denominator. 3.Add to the list in step 2 any factors of the second denominator that do not appear on the list. 4.Form the product of each different factor from the list in step 3. This product is the LCD. Lesson P6 – Day 4

4. Example 1: Finding the Least Common Denominator Step 1: Find the LCD of 4x³ and 10x² Prime Factors of 4x³ : Prime Factors of 10x² : Step 2: LCD =product of the HIGHEST number of occurrences for EACH FACTOR

5. You Try: Find the LCD, then simplify.

6. Simplify with common denominators: Answer:

7. Example 2: 5. x 2 – 3x + 18 (2x-3)(x+3) 5. Combine like terms and Answer: **Sometimes you may have to factor the numerator. **If you have a single expression put it over 1 1.Find a common denominator. :(2x-3)(x+3) 2. (x+2)(x+3) – 4(2x-3) (2x-3)(x+3) (2x-3)(x+3) 2. Multiply the numerator by what is missing in the denominator. 1. (x+2) – 4 (2x-3) (x+3) 3. Multiply numerators. 3. x 2 + 5x + 6 – (8x – 12) (2x-3)(x+3) (2x-3)(x+3) 4. Distribute negative to second numerator and put over common denominator. 4. x 2 + 5x + 6 - 8x + 12 (2x-3)(x+3)

8. Example 3: 1.Write problem and factor both the denominators. Common denominator is: 2. Find common denominator by multiplying the numerators with what is missing from the denominator. 3. Multiply. 4. Distribute the negative and place over same denom. 5. Combine Like Terms

9. YOU TRY! Answer: Summary: Explain how to add and subtract rational expressions with unlike denominators.

10. Class Work: You Try:

11. Class work Answers: