1. AIM: How do we add and subtract rational expressions?
Do Now: Perform the given operation
1) x² + 7x x² - 5x ) 3x + 15 by 2x + 10
x² - 8x x² + 6x x x - 70
HW #8 pg 56 #15-19

2. If the expressions have the same (common) denominator, add or subtract the numerators, keep the same denominator, and simplify the result.

3. To add or subtract fractions with different denominators: 1) find the least common denominator (LCD), 2) change each fraction so that it has that denominator, 3) then add or subtract the numerators. 4) Final Step – Simplify, if possible. Add 5/8 + 6/5

4. To find the LCD factor each denominator write the different factors
give each factor the highest power to which it occurs
multiply the results

5. Subtract:
LCD =
change each fraction to LCD
add/subtract
simplify

6. Add :
LCD =
change each fraction to LCD
add/subtract
simplify

7. Let’s try something more challenging:
2___ ____
x² + x – x² + 2x - 3

8. One for the road:
x²___ x
x² + 7x x + 4