1. Adding and Subtracting Rational Expressions

2. In order to add or subtract fractions we need a common denominator
LCD: 15
LCD: 36
We want the Lowest Common Denominator (LCD) before we add or subtract

3. ADDING and SUBTRACTING RATIONALS - Finding LCM
70x²
10x², 35x²  _______________________
4x³ , 5x²y  _______________________
x-y , x²-y²  _______________________
x²-5x+4 , x – 2  ___________________
20x³y
(x-y)(x+y)
(x-4)(x-1)(x-2)

4. ADDING and SUBTRACTING Adding
ADD/SUBTRACT Rules
Factor denominators
Find LCM
Multiply each term to get denominator = LCM
+/- and combine like terms
Simplify more if possible

5. ADDING and SUBTRACTING Subtracting
Factor denominators
Multiply terms to get LCMs on bottom
Simplify
Simplify
Combine like terms
Factor top

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10. ADDING and SUBTRACTING A Toughie
FACTOR
FACTOR -OUT
CONVERT
SIMPLIFY
COMBINE
SIMPLIFY

11. The goal is to simplify them down
COMPLEX FRACTIONS
What are complex fractions?
Complex fractions are giant expressions
where there are fractions within fractions.
The goal is to simplify them down
to normal fractions.

12. EX – simplify SIMPLIFYING COMPLEX FRACTIONS STEPS Find LCM of denoms
Treat each fraction as an individual problem. Find the LCM and add or subtract.
Divide the rational expressions.
Simplify

13. EX - simplify DIVIDE THE RATIONALS DISTRIBUTE LCM FACTOR OUT -1
MULT TOP/BOT by LCM
SIMPLIFY

14. Let’s try one

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