Solving Quadratic Equations by Completing the Squares

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

What is the first step to solving the 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
• Write the trinomial as a square of binomial.
• Subtract the 21

Find the missing value "c" to create a perfect square trinomial:
x² – 8x   ___ 

• -4
• -16
• 4
• 16

What is the next step to solving the equation by completing the square?
a² - 24x - 16 = 20

• Set the equation equal to zero.
• Add 16 to both sides.
• Write the trinomial as a square of binomial.
• Divide -24 by 2 , then square and add the result to both sides.

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

When solving the equation x² - 12x + 4 = 20
by completing the square , what goes on the left side of the equation?
(_____)² = 16

• x  - 12
• x + 6
• x - 6
• x - 8

Solve     2x² - 50 = 0

• 25
• -5, 5
• -5i , 5i
• 25i

Solve the equation (x + 3)² = 49.

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

When solving x² - 4x + 3 = 8,
what goes in the blank?
(x  - 2)² = _____

• 8
• 5
• 9
• 11

What is the next step when solving x² + 6x = 5 by Completing the Square?

• (x + 3)² = 5
• (x + 6)² = 9
• (x + 3)² = 14
• (x + 6)² = 14