8.7 Complete The Square

What do you do to the b value to correctly complete the square?

• square it
• divide it by 2 and square the result
• divide it by 2 and take the square root of the result
• divide it by 2 only

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

When factoring
x² - 4x + 4 = 20,
what goes in the blank?
(x - __ )² = 20

• 4
• 2
• 8
• 20

What value of c would make this a perfect sqaure trinomial?
x² +8x + c

• 4
• 16
• 64
• -16

What value of c would make this a perfect square trinomial?
x² + 2x + c

• 2
• 4
• -2
• 1

What value of c would make this a perfect square trinomial?
x² - 12x + c

• 36
• 24
• 144
• -36

Complete the Square (this is step before you take square root on both sides)

x² + 6x = 5

• (x + 3)² = 5

• (x + 6)² = 9

• (x + 3)² = 14

• (x + 6)² = 14

Find the missing value "c" to create a perfect square trinomial:
x² + 26x + ___ 

• 13
• 136
• 169
• 26

Complete the square.
x² + 6x + ____

• x² + 6x + 9
• x² + 6x - 36
• x² + 6x + 36
• x² + 6x - 9

 $x^2+8x+c=20+c$  

Rewrite the above equation into a perfect square binomial form. 
(𝑥 +_______) $^2$ = ________

•  $\left(x-4\right)^2=4$  

•  $\left(x+4\right)^2=36$  

•  $\left(x-8\right)^2=12$  

•  $\left(x+8\right)^2=28$