9.5 Adding and

Subtracting Rational Expressions

Adding and Subtracting

Add:

To add or subtract fractions, you must first:

9

2

5

3

Example 1. Find the Least Common Multiple (What would be your common denominator?)

a. 4x2 – 36 6x2 + 36x + 54

We’re looking for:

b. 3x2 – 9x – 30 6x + 30

c. 5x2 + 15x + 10 2x2 - 8

Example 2. Add.

a. 3x3

x5

4x5x

12

b. x8x4

x3

12x4x

122

Example 3. Subtract.

a.

15y3

4

125y5

y72

b. 30x6

x3

105x36x3

22

Example 4. Simplify.

4y

5

3x

1

2 options to simplify:

1.

2.

Assignment

Pg 507 #4 – 40e