Completing the Square and Quadratic Formula

What is the quadratic formula?

• $x=\frac{b-\sqrt{\left(b\right)^2-4\left(a\right)\left(c\right)}}{2\left(a\right)}$

• $x=\frac{-\left(b\right)\pm\sqrt{\left(b\right)^2-4\left(a\right)\left(c\right)}}{2\left(a\right)}$

• $x=\frac{\left(b\right)\pm\sqrt{\left(b\right)^2-4\left(a\right)\left(c\right)}}{2a}$

• $x=-\left(b\right)\pm\sqrt{b\pm4\left(a\right)\left(c\right)}$

Tags

CCSS.HSA-REI.B.4B

Which equation shows  $x^2+8x+9=0$  after the method of completing the square has been applied?

•  $\left(x+2\right)^2=-5$  

•  $\left(x+4\right)^2=7$  

•  $\left(x+8\right)^2=55$  

•  $x^2=-\left(8x+9\right)$  

Tags

CCSS.HSA-REI.B.4B

 $2x^2+3x-4=0$  When the quadratic formula is applied to , what is the numerator of the simplified answer?

•  $3\pm\sqrt{41}$  

•  $-3\pm\sqrt{41}$  

•  $3\pm\sqrt{38}$  

•  $-3\pm\sqrt{-23}$  

Tags

CCSS.HSA-REI.B.4B

Solve  $x^2+10x=39$  .

•  $x=-5\pm\sqrt{14}$  

•  $x=-3\ or\ 13$  

•  $x\ =\ 3\ or\ -13$  

•  $x=5\pm\sqrt{14}$  

Tags

CCSS.HSA-REI.B.4B

What are the solutions of the equation  $x^2=23+2x$  ?

•  $x=-1\pm2\sqrt{6}$  

•  $x=1\pm2\sqrt{6}$  

•  $x=-1\pm\sqrt{22}$  

•  $x=1\pm\sqrt{22}$  

Tags

CCSS.HSA-REI.B.4B

Find the zeros of  $f\left(x\right)=x^2+7x+9$  .

•  $x=-7\pm\sqrt{13}$  

•  $x=\frac{-7\pm\sqrt{13}}{2}$  

•  $x=\frac{3\pm\sqrt{7}}{2}$  

•  $x=3\pm\sqrt{7}$  

Tags

CCSS.HSA-REI.B.4B

What is this formula?

• This is the speed of light formula.
• This is the quadratic formula.
• This is the zero product property.
• This is scary.

Tags

CCSS.HSA-REI.B.4B

Complete the square for
x² + 12x + ____

• x² + 12x + 144
• x² + 12x + 36
• x² + 12x - 36
• x² + +12x - 144

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

Find the value of c that makes x² + 16x + c a perfect square.

• -64

• 64

• 8

• 16

Tags

CCSS.HSA-REI.B.4B