3.2 and 3.3 Review - Solve Quadratics

Solve by factoring!

Use the X Method.

• -2, 4

• -8

• ±8

• No real solution

Answer explanation

Numbers that multiply to be -8 and add to be -2.

Your numbers are -4 and 2 so,

(x - 4)(x + 2)=0

x - 4 = 0

(add 4)

x = 4

x + 2 = 0

(subtract 2)

x = -2

What are the zeros?

• x= 0 and x= -4
• x= 0 and x= 4
• y= 0
• x= 2

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

Answer explanation

Numbers that multiply to be 20 and add to be -9.

Your numbers are -4 and -5 so,

(x - 4)(x - 5)=0

x - 4 = 0

(add 4)

x = 4

x - 5 = 0

(add 5)

x = 5

What is another word that describes the zeroes of a quadratic function?  

• y-intercepts
• vertex
• x-intercepts
• maximum

What are the solutions of this graph?

• -2 and 3

• -1/2 and -6

• -2 and -6

• 3 and -6

How many zeros does this graph have?

• None

• One

• Two

• Can not be determined

How many solutions does this graph have?

• one
• two
• no real solutions
• cannot be determined

• Divide 18 by 2, then square that number and add it to both sides of the equation

• Square 18 and then add it both sides of the equation

• It already is a perfect square

• Subtract 18x from both sides and then divide both sides by x to find the answer

What is the first step to solving THIS equation by completing the square?

a² + 10a + 21 = 0

• Set the equation equal to zero

• Divide 10 by 2 and add the result to both sides

• Add a² and 10a together

• Subtract the 21

What should be added to both sides of the following equation to complete the square?
x² + 12x = 5

• 12
• 6
• 36
• 5