Factoring: Special Cases

Factor by using GCF:

 $10x^2+15x-5$  
Remember that the answer should be written as GCF(quotient)

• 25(10x³ + 45x - 15)

• 5(2x³ + 3x² - x)

• x(10x³ + 15x - 5)

• 5(2x² + 3x - 1)

• ( x + 5 ) ( x - 5 )

• ( x - 5 ) ( x - 5 )

• ( x + 5 ) ( x + 5 )

• Prime

• (5x-9)²

• (5x+9)(5x-9)

• 25(x-9)²

• (9x+5)(9x-5)

Factor 25x² - 81.

• (5x² - 9²)²

• (5x + 9) (5x + 9)

• (5x + 9) (5x - 9)

• (5x - 9) (5x - 9)

Factor 121r² - 64t²

• (11r + 8t) (11r - 8t)

• (11r - 8t) (11r - 8t)

• (11r + 8t) (11r + 8t)

• (11r² + 8t) (11r + 8t²)

Factor completely: 
3x² + 18x +15
Hint: Factor GCF first.

• 3(x² + 6x + 5)
• (x + 5)(x + 1)
• 3(x + 5)(x + 1)
• Prime

Factor
x² + 9x - 36

• (x + 12)(x - 3)
• (x + 9)(x - 4)
• (x - 12)(x + 3)
• (x - 9)(x - 4)

Factor
n² + 16n + 63

• (n-7)(n+4)
• (n+7)(n-9)
• (n-3)(n-10)
• (n+7)(n+9)

Factor
k² - 2k - 24

• (k+4)(k-6)
• (k+4)(k+6)
• (k+6)(k-1)
• (k-4)(k+6)

Factor:
 b² + 8b + 7

• (b + 4)(b + 3)
• (b + 6)(b + 1)
• (b + 7)(b +1)
• prime