The Quadratic Formula

This lesson covers:

  1. How to use the quadratic formula to find the solutions of a quadratic
  2. How to express these solutions in both surd and decimal form

Using the quadratic formula, what are the solutions to the following quadratic?

(Give your answer in form 𝑎 ± √𝑏)

x2−8x+14=0

3 ± √2

5 ± √3

4 ± √2

0

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1

Using the quadratic formula, what are the solutions to the following quadratic?

(Give your answer in form 𝑎 ± √𝑏)

x2+2x−7=0

1 ± 2√4

-1 ± 2√2

-2 ± 2√2

0

/

1

Using the quadratic formula, what are the solutions to the following quadratic?

(Give your answer in form 𝑎 ± √𝑏)

x2−4x−1=0
5

2 ± √

2 ± √

0

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1

Using the quadratic formula, what are the solutions to the following quadratic?

(Give your answer to 2 decimal places)

x2+5x+3=0

-0.50 or -3.34

-0.70 or -4.30

-0.44 or -2.30

0

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1

Using the quadratic formula, what are the solutions to the following quadratic?

(Give your answer to 2 decimal places)

3x2+2x−13=0

1.77 or -2.44

1.80 or 2.50

-1.78 or 2.45

0

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1

Using the quadratic formula, what are the solutions to the following quadratic?

(Give your answer to 2 decimal places)

3x2−11x−13=0

-4.61 or 0.94

-4.61 or -0.94

4.61 or -0.94

0

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1

Using the quadratic formula, what are the solutions to the following quadratic?

(Give your answer to 2 decimal places)

5x2=6x+3

1.58 or -0.38

-1.58 or -0.38

-1.58 or 0.38

0

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1