9-2 Practice ALG

Solve by factoring:
 x² - 9x + 20 = 0

• x = -4 and x = -5
• x = 20 and x = -9
• x = 4 and x = 5
• x = -4 and x = 5

Solve by factoring
a² - 9a + 8 = 0

• a = -8, 1
• a = -8, -1
• a = 8 , 1
• a = 2,4

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

Which equation matches these solutions? x=5,-7

• (x+5)(x-7)=0
• (x-5)(x+7)=0
• (x+5)(x+7)=0
• (x-5)(x-7)=0

Solve  $\left(3x-7\right)\left(2x-8\right)=0$  for x

•  $x=-\frac{7}{3}$  or  $x=4$  

•  $x=-\frac{7}{3}$  or  $x=-4$  

•  $x=\frac{7}{3}$  or  $x=4$  

•  $x=\frac{7}{3}$  or  $x=-4$  

Solve using Zero-Product Property:
 $(2x-2)(5x+5)=0$  

• x = -1

• x = -1 or x = 1

• x = 1

• x = -2 or x = 5

What should you do first in solving this equation?
x² + 6x - 13 = 3

• Get factored form
• Find two numbers which add to make 6 and multiply to make -13
• Make it equal 0 by subtracting 3 on each side
• Type it all in a calculator.

.How many roots does this parabola have?

• 3

• 2

• 0

• 1

Use the graph to determine the roots.

• -1 and -3
• 1 and -3
• 1 and 3
• -1 and 3

Find the zeros of the equation: 
(x+10)(x-2) = 0

• 10 and 2
• -2 and 10
• -10 and 2
• -2 and -10