You know two methods of solving quadratic equations:

- Cards:

- Factorising: A x B = 0, then A = 0 or B = 0

When to use which method?

Slide 3 - Slide

A. Solving quadratic equations with CARDS

Question 1: Can you use cards?

(You can use cards if the equation contains only 1 variable)

Yes? Solve using cards.

No? Go to B, for Factorising Binomials and Trinomials

Slide 4 - Slide

A. Solving quadratic equations with cards

Use the balance method (add/subtract the same amount, divide/multiply by the same number , take the square root on both sides of the equal sign, don't forget the second solution)

Slide 5 - Slide

B. Solving quadratic equations

by Factorising

Question 2: Is one side of the equation equal to 0?

Yes?

See examples next slide. We only factorise,

soon we'll solve it too!

No? Reduce to zero

Slide 6 - Slide

Factorise binomial

Find the largest common factor and place in front of a set of single brackets, fill in the remaining factors inside the brackets.

(See §11.2). Note: the 3rd example has to be made equal to 0 first!

Slide 7 - Slide

Reduce to zero

Use the balance method (add/subtract the same term on both sides of the equal sign).

Slide 8 - Slide

Factorise trinomial

Find two numbers that have the number in front of x as a sum and the single numbers as a product. Write as (x + ...)(x + ...).