Factoring AC Method, Grouping, Difference of Squares

What is ALWAYS the first step when factoring?

• Look for the GCF

• Write a, b, and c

• Difference of squares

• Group

Factor 4x²-9

• (4x-9)(4x+9)

• (2x-3)(2x+3)

• 2x-3

• (2x-4.5)(2x+4.5)

Fully Factor the Following
25x²-81

• (5x-9)²
• (5x+9)(5x-9)
• 25(x-9)²
• (9x+5)(9x-5)

9x² - 49y²

• ( 3x + 7y²) (3x + 7y²)

• ( 3x - 7y) (3x + 7y)

• ( 3x - 7y³) (3x - 7y³) 

• Prime

3x² - 75

• 3( x + 5 ) ( x - 5 ) 
• Prime
• ( x + 5 ) ( x - 5 ) 
• 3( x - 5 ) ( x - 5 ) 

16p³ - 81q⁶

• (4p + 9q) (4p - 9q)
• (4p² + 9q³) (4p - 9q³)
• (4p² + 9q) (4p - 9q)
• Can't factor using Diff. of Squares

r⁴ - q⁴

• (r² + q²) (r² - q²)
• (r² - q²) (r² - q²)
• (r + q) (r - q)
• Can't factor using Diff. of Squares

9n² + 1

• (3n + 1) (3n - 1)
• (3n - 1) (3n - 1)
• (n + 3) (n - 3)
• Can't factor using Diff. of Squares

r² - 9t²

• (r + 3t) (r - 3t)
• (r - 3t) (r - 3t)
• (3r + t) (3r - t)
• Can't factor using Diff. of Squares

36x² - 64

• (6x - 8)(6x + 8)
• 4(3x - 4)(3x + 4)
• Not Factorable
• (9x - 16)(9x + 16)