# Algebra L3 Sample Pages

These are sample pages for the Edexcel Algebra Award Level 3 workbook.

- Created by: Peter
- Created on: 04-04-13 16:56

First 243 words of the document:

Chapter 4 Quadratic equations

4 Solve by completing the square.

Step into AS

a (x 2 4)(x 1 2) 5 5 b 2x 2 1 6x 2 7 5 0 c x 2 2 5x 1 3 5 0

x5 or x 5 x5 or x 5 x5 or x 5

Needs more practice Almost there I'm proficient!

AS LINKS

Solving by using the formula C1: 2.5 Solving

4.3

quadratic

equations by us

ing the

By the end of this section you will know how to: formula

Solve quadratic equations by using the formula

Key points

Any quadratic equation of the form ax 2 1 bx 1 c 5 0 can be solved using the formula

________

2b 6 b 2 4ac

2

x 5 _______________

2a

2

If b 2 4ac is negative then the quadratic equation does not have any real solutions.

It is useful to write down the formula before substituting the values for a, b and c.

Hint

1 Solve x 2 1 6x 1 4 5 0 Identify a, b an 2 Solve 3x 2 2 7x 2 2 5 0

Guided

d

Give your solutions in surd form. c and substitut

e

Give your solutions in surd form.

them into the

formula.

a 5 1, b 5 6, c 5 4 a5 , b 5 27, c 5

_________________________ _________________

2( ) 6 ( 2

) 24 6 2

x5 x5

2 2

____________ ____________

6 2 6 2

x5 x5

_____ _____

6 6

x5 x5

____________ _____ _____

6 1 2

x5 x5 or x 5

_____ _____

1 2

x5 or x 5 The solutions are x 5 or x 5

The solutions are x 5 or x 5

23

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