Solving Quadratic Equations and Discriminant

If b² - 4ac is positive, then the quadratic equation has:

• zero solutions

• two different solutions

• 1 solution

• none of these

Solve the following quadratic equation: 4x² - 5x - 9 = 0

(Use factoring or the Quadratic Formula)

• {-1, 9/4}

• {1, 9/4}

• { 2, 3}

• {-2, -3}

What is the discriminant and how many solutions would this quadratic have?

-8x² - 4 = -6x

• -92, No Solutions

• 164, 2 Solutions

• -164, No Solutions

• 92, 2 Solutions

Solve the following quadratic equation by graphing:

-x²-2x+3=-5

• {-3,-1}

• {-2,0}

• {-4,2}

• {-1,4}

Solve by factoring: x² + 3x - 18 = 0

• x = -3 and x = 6

• x = 3 and x = -6

• x = -9 and x = 2

• x = 9 and x = -2

Solve by using the quadratic formula:

5b² - 4 = 41

• b = 9, b = -9

• b = 3, b = -3

• b = 8, b = -8

• no real solution

What should you do first to solve this equation using quadratic formula?

x² + 6x - 13 = 3

• Get factored form

• Write down: a=1, b=6, c=-13

• Make it equal 0 by subtracting 3 on each side

• Type it all in a calculator.

What is the first step to solving THIS equation by completing the square?

a² + 10a + 21 = 0

• Leave the equation equal to zero

• Divide 10 by 2 and add the result to both sides

• Add a² and 10a together

• Subtract 21 from both sides

When solving a quadratic equation, 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