Warm-up:

Homework:

9.b multiply and divide rational expressions

After this lesson you will be able to…

Factor and reduce rational expressions during multiplication

Convert division problems into multiplication

Multiplying Rational Functions

The BASICS: To multiply two rational expressions, multiply numerators x numerators and denominators x denominators

3 2 2

4

25 915 10

x y x yxy y

BIG IDEA

You can reduce BEFORE you multiply!!!

Procedure

1. Factor each numerator and each denominator completely.

2. Reduce from top to bottom.3. Whatever is left, multiply numerator x

numerator and denominator x denominator

3 2 2

4

25 915 10

x y x yxy y

Example 1:

4 2 2 3

4 5

12 2118 4a b a bab a b

Example 2:

2

3 15 35 6 6 30

x xx x x

Example 3:

2

3 2

3 6 5 105 6 24m m mm m

Dividing rational expressions

BIG IDEA!!!

Change the division to multplication!

Procedure:

1. Flip the 2nd fraction and change to multiplication.

2. Factor and reduce, then multiply.

2 3 3

5 4

6 127 5m n mnmn m n

Example 4:

221

2 15 10x

x xx

Example 5:

2

7 21 34 6 12

y yy y

Homework:

HW ST 9.b