Four Ways to Solve Quadratic Equations

Select the best answer.

• A

• B

• C

• D

Solve by factoring.
z² - 18z + 81 = 0

• z = 9

• z = -9

• z = 9 or z = -9

Solve by factoring.
x² + 2x - 8 = 0

• 4 and 2

• 4 and -2

• -4 and 2

• -4 and -2

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

Solve by completing the square:
k² − 12k + 23 = 0

• {6 + √13, 6 - √13}

• {-6 + √13, -6 - √13}

• {6 + √59, 6 - √59}

• {-6 + √59, -6 - √59}

Solve Using the Quadratic Formula 
2x² + 7x - 15 = 0

• -1.5 or 5

• No Solution

• -5 or 1.5

• 0.7 or 5

Find the discriminant and determine how many zeros exist for the following function: 
x² - 6x + 5 = 0

• -56; No real roots

• 4; Two real solutions

• -56; Two real solutions

• 4; No real roots

Solve using the Quadratic Formula.

• A

• B

• C

• D

The discriminant is

• aX²  + bX  +  c

• b - 4ac

• b² - 4ac

• b² + 4ac

Solve by taking square roots:

4x² - 1 = 48

• x = 7/2 or -7/2

• x = 2/7 or -2/7

• x = 49/4 or -49/4

• x = 47/4 or -47/4