Solving Quadratic Equations by Completing 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

Tags

CCSS.HSA-REI.B.4B

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

Tags

CCSS.HSA-REI.B.4B

When do you use the plus or minus symbol?
±

• After taking the square root of both sides
• After adding the square to both sides
• After taking half of b
• After setting the equation equal to zero

Tags

CCSS.HSA-REI.B.4B

Solve the following quadratics equation by completing the square...

x² + 4x + 1 = 0

• x = -2 ± √3

• x = -3 ± √2

• x = 2 ± √3

• x = 2 ± √2

Tags

CCSS.HSA-REI.B.4B

Solve the following quadratics equation by completing the square...

x² + 12x + 8= 0

• x = -6 ± 2√7

• x = 6 ± 2√7

• x = 28 ± √6

• x = -28 ± √6

Tags

CCSS.HSA-REI.B.4B

Solve the equation by completing the square and then finding the roots. 
x²+ 6x - 4 = 36

• x = -7, 7
• x = 4, -10
• x = -4 +- √7
• x = 10, -4

Tags

CCSS.HSA-REI.B.4B

Solve. x² + 4x - 16 = 0

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Tags

CCSS.HSA-REI.B.4B

 $v^2+2v-23=0$  

•  $\left\{9,1\right\}$  

•  $\left\{-2,-12\right\}$  

•  $\left\{-2+3\sqrt{3},-2-3\sqrt{3}\right\}$  

•  $\left\{-1+2\sqrt{6},\ -1-2\sqrt{6}\right\}$  

Tags

CCSS.HSA-REI.B.4B

Solve by completing the square.
 $x^2-4x-20=0$  

•  $x=\left\{-2\pm6\sqrt{2}\right\}$  

•  $x=\left\{2\pm6\sqrt{2}\right\}$  

•  $x=\left\{2\pm2\sqrt{6}\right\}$  

•  $x=\left\{-2\pm2\sqrt{6}\right\}$  

Tags

CCSS.HSA-REI.B.4B

Solve.
 $x^2-16x+48=0$  

•  $x=\left\{-12,\ 4\right\}$  

•  $x=\left\{-12,\ -4\right\}$  

•  $x=\left\{-4,\ 12\right\}$  

•  $x=\left\{4,\ 12\right\}$  

Tags

CCSS.HSA-REI.B.4B