1. Adding and Subtracting Rational Expressions
We can add or subtract rational expressions by combining like terms if we have the same denominator.
The challenge will be to find a common denominator!

2. Adding or subtracting rational expressions with a common Denominator
𝑝 𝑞 + 𝑅 𝑄 = 𝑃+𝑅 𝑄
𝑥 4 + 5𝑥 4 = 6𝑥 4
6𝑥 4 = 3𝑥 2

3. Another example
𝑥 3 𝑦 2 − 𝑥+1 3 𝑦 2 = ?
− 1 3 𝑦 2

4. Finding the Least common denominator
Step 1: factor each denominator completely
Step 2: The LCD is the product of all unique factors, each raised to a power equal to the greatest number of times that the factor appears in any factored denominator.

5. An example (I do) find the lcd
7 20 𝑎 2 𝑏 3 & 9 15𝑎 𝑏 4 𝑖𝑠 ?
60 𝑎 2 𝑏 4

6. An example (I do) find the lcd
𝑥+4 𝑥 2 −36 & 𝑥 𝑥 2 +12𝑥+36 = ?
𝑥−6 𝑥+6 2

7. We do—find the LCD
2 3 𝑥 5 𝑦 2 & 3𝑧 5𝑥 𝑦 3 =
15 𝑥 5 𝑦 3

8. Another (we do) find the LCD
𝑚−1 𝑚 2 −25 & 2𝑚 2 𝑚 2 −9𝑚−5 = ?
(𝑚+5)(𝑚−5)(2𝑚+1)

9. A short video

10. Assignments Already assigned Already Assigned pg 345-346
Problems 33-44
pg 346
Problems 45-56
NEW ASSIGNMENT:
PG PROBLEMS 1-26