IM2 - Solve Quadratic Equations

Using the graph solve the equation
-x²-2x+3=-5.

• {-3,-1}
• {-2,0}
• {-4,2}
• {-1,4}

Use the graph of y=-x²+6x-5 to solve the equation -x²+6x-5=0

• {-1,5}

• {3,4}

• {1,5}

• {2,4}

Solve by factoring: x² - 9x + 20 = 0

• x = -4 and x = -5
• x = 20 and x = -9
• x = 4 and x = 5
• x = -4 and x = 5

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

2d² = 8

• 4
• -2
• -4, 4
• -2, 2

Solve by taking square roots:

5b² - 4 = 41

• b = 9, b = -9

• b = 3, b = -3

• b = 8, b = -8

• no real solution

Solve for x:

(x + 6)² = 49

• x=7,12

• x=±7

• x=1,-13

• x=43,-55

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.

In the equation

x² - 5x + 7= 0,

match each leading coefficient with its correct letter

for a, b and c

• a = 0, b = 5, c = 7

• a = 1, b = -5, c = 7

• a = 7, b = 5, c = 1

• a = 1, b = 5, c = 7

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