L2 - Unit 7B Factoring

Unit 7B Factoring

Difference of Squares

Warm Up

(Simplify the following)

• 1. (x+4)(x-4)

• 2. (5m+1)(5m-1)

• 3. (2a+3b)(2a-3b)

Warm Up Review

Answers

• A1. x²-4x+41-16 => x² - 16

• A2. 25m²-5m+5m-1 => 25m² - 1

• A3. 4a²-6ab+6ab-9b² => 4a² - 9b²

Students will be able to..

• Identify when to use the Difference of Squares Rule in factoring.

• Successfully use the Difference of Squares Rule to factor an expression.

• Identify when NOT to use this method.

• Recognize and Factor the GCF when applicable.

Difference of Squares

• 1. Make sure you have a subtraction sign! Also be sure you can take sq rt of both coefficients.

• 2. Use the rule!

• 3. Check your work by distributing.

Multiple Select

Check all that apply:

$$a^2-4$$  

• I see a minus sign!

• I can take sq root of a^2

• I can take sq root of 4

• I can factor this with difference of squares rule.

• The answer is prime.

Multiple Select

Check all that apply:

$$1\ -\ 49y^2$$  

• I see a minus sign.

• I can take sq root of 1

• I can take sq root of 49y^2

• I can factor this using the difference of square rule.

• The answer is prime.

Multiple Select

Check all that apply:

$$k^2+25$$  

• I see a minus sign.

• I can take sq root of k^2

• I can take sq root of 25

• I can factor using the difference of squares rule.

• The answer is prime.

Let's take it up a notch...

First check for a GCF!

Next see if you can use the Difference of Squares Rule!!

I'll walk you through the first one!!

• I can take 2 out of both terms-- GCF!!

• Now I have 2(n^2 - 36)...

• I see a subtraction sign, I can take sq root of both terms... Difference of Squares

• 2(n+6)(n-6) would be the factored form!!

IXL PRACTICE

​

• IXL Skill X6 Factoring Special Cases (60+)

• IXL Skill X3 Algebra Tiles