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Learn the concepts of factoring in algebra and geometry, including GCF and Difference of 2 Squares methods. Practice problems and examples included.
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Essential Question: • What is Factoring and How Can I use it? Adapted by Christopher Carnes, Rancho Viejo MS, Hemet, CA 2/3/2016
Factoring Expressions Greatest Common Factor (GCF) Difference of 2 Squares
Objectives • I can factor expressions using the Greatest Common Factor Method (GCF) • I can factor expressions using the Difference of 2 Squares Method
What is Factoring? • Quick Write: Write down everything you know about Factoring from Algebra-1 and Geometry? • You can use Bullets or give examples • 2 Minutes • Share with partner!
Factoring? • Factoring is a method to find the basic numbers and variables that made up a product. • (Factor) x (Factor) = Product • Some numbers are Prime, meaning they are only divisible by themselves and 1
Method 1 • Greatest Common Factor (GCF) – the greatest factor shared by two or more numbers, monomials, or polynomials • ALWAYS try this factoring method 1st before any other method • Divide Out the Biggest common number/variable from each of the terms
Greatest Common Factorsaka GCF’s Find the GCF for each set of following numbers. Find means tell what the terms have in common. Hint: list the factors and find the greatest match. 2, 6 -25, -40 6, 18 16, 32 3, 8 2 -5 6 16 1 No common factors? GCF =1
Find the GCF for each set of following numbers. Hint: list the factors and find the greatest match. x, x2 x2, x3 xy, x2y 2x3, 8x2 3x3, 6x2 4x2, 5y3 Greatest Common Factorsaka GCF’s x x2 xy 2x2 3x2 1 No common factors? GCF =1
Factor out the GCF for each polynomial:Factor out means you need the GCF times the remaining parts. a) 2x + 4y 5a – 5b 18x – 6y 2m + 6mn 5x2y – 10xy Greatest Common Factorsaka GCF’s 2(x + 2y) How can you check? 5(a – b) 6(3x – y) 2m(1 + 3n) 5xy(x - 2)
FACTORING by GCF -2x2 5xy( ) 3y + 5y2
FACTORING (x3 – 4x2 + 2x – 3) 2x
Ex 1 • 15x2 – 5x • GCF = 5x • 5x(3x - 1)
Ex 2 • 8x2 – x • GCF = x • x(8x - 1)
Ex 3 • 8x2y4+ 2x3y5 - 12x4y3 • GCF = 2x2y3 • 2x2y3(4y + xy2 – 6x2)
Method #2 • Difference of Two Squares • a2 – b2 = (a + b)(a - b)
What is a Perfect Square • Any term you can take the square root evenly (No decimal) • 25 • 36 • 1 • x2 • y4
Difference of Perfect Squares x2 – 4 = the answer will look like this: ( )( ) take the square root of each part: ( x 2)(x 2) Make 1 a plus and 1 a minus: (x + 2)(x - 2 )
FACTORING (x – 8)(x + 8)
Example 1 • (9x2 – 16) • (3x + 4)(3x – 4)
Example 2 • x2 – 16 • (x + 4)(x –4)
Ex 3 • 36x2 – 25 • (6x + 5)(6x– 5)
More than ONE Method • It is very possible to use more than one factoring method in a problem • Remember: • ALWAYS use GCF first
Example 1 • 2b2x – 50x • GCF = 2x • 2x(b2 – 25) • 2nd term is the diff of 2 squares • 2x(b + 5)(b - 5)
Example 2 • 32x3 – 2x • GCF = 2x • 2x(16x2 – 1) • 2nd term is the diff of 2 squares • 2x(4x + 1)(4x - 1)
Exit Slip • On your notes, write these 2 things: • 1. Define what factors are? • 2. What did you learn today about factoring?
Homework • WB Page 125, 1-21 Odd