Alg 1: Completing the Square Practice

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

To solve by completing the square, what needs to be moved in this equation?
x² = 9 - 4x

• the -4x
• the 9
• the x²

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

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

What is one of the solutions to this equation?
(2x - 1)² = 49

• 7
• -7
• -4
• -3

Solve the following equation by completing the square:
n² - 2n - 3 = 0

• {3, -1}
• {4, -4}
• {5, -3}
• {8, -7}

Solve the following equation by completing the square:
n² = 18n + 40

• {11, -11}
• {16, 2}
• {20, -2}
• {10, -4}

Simplify √56

• 4√14
• 2√14
• 2√27
• 4√7

Simplify √800.

• 10√8
• 5√32
• 12√2
• 20√2