Solving Quadratic Equations

 $x^2-225=0$  Solve the quadratic equation

•  $x=\pm15$  

•  $x=15$  

•  $x=\pm25$  

• No solution

 $4x^2-1=0$  Solve the quadratic equation

•  $x=\frac{1}{2}$  

•  $x=\pm\frac{1}{4}$  

•  $x=\pm\frac{1}{2}$  

• No solution

 $x^2+1=-80$  

•  $x=\pm9$  

•  $x=9$  

•  $x=-9$  

• No solution

What number should be added to complete the square?

• 7

• 14

• 49

What number should be added to complete the square?

• -9

• 9

• 12

• 36

What number should be added to both sides of the equation to solve by completing the square?

• -100

• -40

• 40

• 100

Robert is using the completing the square method to solve the quadratic equation. His first two steps are shown below. What number should go in the blank?

• 2

• 4

• -2

• -4

Solve the quadratic equation using the method of your choice.

• x = -11 and x = 3

• x = 11 and x = 3

• x = -11 and x = -3

• x = 11 and x = -3

Solve the quadratic equation using the method of your choice.

• x = -5 and x = -13

• x = 5 and x = -13

• x = -5 and x = 13

• x = 5 and x = 13

Use the quadratic formula to solve $x^2+9x+9=0$  

•  $x=\frac{9\pm\sqrt{45}}{2}$  

•  $x=\frac{-9\pm\sqrt{45}}{2}$  

•  $x=\frac{9\pm\sqrt{45}}{1}$  

•  $x=\frac{-9\pm\sqrt{-25}}{2}$