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!

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

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

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.

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

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

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

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

A short video https://www.youtube.com/watch?v=XTZl7Kn6u4Y

Assignments Already assigned Already Assigned pg 345-346 Problems 33-44 pg 346 Problems 45-56 NEW ASSIGNMENT: PG. 353-354 PROBLEMS 1-26