Solving Quadratics by Factoring

Factor
k² - 2k - 24

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

Factor
3a² + 4a + 1

• (7a-10)(a-8)
• Not factorable
• (3a+1)(a+1)
• (3a-1)(a-1)

Factor
3v² - 4v - 7

• (3v-7)(v+1)
• 3(v-7)(v-1)
• (3v+1)(v-9)
• (3v+1)(v-10)

What is the first step in solving 
(x + 2)(x - 3) = 0      ?

• Plug in zero for x
• Solve for x
• FOIL
• Set each binomial factor equal to zero

Solve
x² + 2x - 24 = 0

• x = -6, x = 4
• x = 6, x = -4
• x = 12, x = -2
• x = 8, x = -3

Solve
6x² + 17x + 12 = 0

• x = -4/3, x = -3/2
• x = 9, x = 8
• x = 4, x = 3
• x = -4, x = -3

Solve
x² + 9x + 20 = 0

• x = -2, x = -10
• x = -3, x = -4
• x = -4, x = -5
• x = -4, x = -6

Solve
x² + 7x + 12 = 0

• x = -2, x = -10
• x = -3, x = -4
• x = -4, x = -5
• x = -4, x = -6

Solve
x² + 13x + 12 = 0

• x = -1, x = -12
• x = -1, x = -24
• x = -2, x = -6
• x = -2, x = -12

Solve:   $3x^2=9x$  

•  $x=3$  and  $x=-3$  

•  $x=3$  

•  $x=0$  and  $x=9$  

•  $x=0$  and  $x=3$