1. Factorising Quadratics
Special Cases

2. Did I get it? Can I factorise the special cases?
𝟏𝟎−𝟕𝒙+ 𝒙 𝟐
𝟐 𝒙 𝟐 −𝟔𝒙−𝟖
𝟒𝒙 𝟐 −𝟖𝟏

3. Last Objective on Factorising….
To be able to make calculations using factorising (without a calculator)
Let’s go over all the factorising question types we did….
Then we’ll figure out, which of these we must use to be able to make calculations using factorising.

4. 𝑭𝒂𝒄𝒕𝒐𝒓𝒊𝒔𝒆 𝟒𝒂 𝟐 −𝒂
𝒂(𝟒𝒂−𝟏)

5. 𝑭𝒂𝒄𝒕𝒐𝒓𝒊𝒔𝒆 𝒙 𝟐 +𝟐𝟎𝒙+𝟑𝟔
(𝒙+𝟐)(𝒙+𝟏𝟖)

6. 𝑭𝒂𝒄𝒕𝒐𝒓𝒊𝒔𝒆 𝒙 𝟐 −𝟔𝒙+𝟗
(𝒙−𝟑) 𝟐

7. 𝑭𝒂𝒄𝒕𝒐𝒓𝒊𝒔𝒆 𝒙 𝟐 −𝟗𝒙−𝟐𝟐
(𝒙−𝟏𝟏)(𝒙+𝟐)

8. 𝑭𝒂𝒄𝒕𝒐𝒓𝒊𝒔𝒆 𝟖+ 𝒙 𝟐 −𝟗𝒙
𝒙 𝟐 −𝟗𝒙+𝟖 (𝒙−𝟏)(𝒙−𝟖)

9. 𝑭𝒂𝒄𝒕𝒐𝒓𝒊𝒔𝒆 𝒙 𝟐 − 𝒚 𝟐
(𝒙−𝒚)(𝒙+𝒚)

10. 𝑭𝒂𝒄𝒕𝒐𝒓𝒊𝒔𝒆 𝟓𝒙 𝟐 −𝟏𝟓𝒙−𝟓𝟎
𝟓( 𝒙 𝟐 −𝟑𝒙−𝟏𝟎) 𝟓(𝒙−𝟓)(𝒙+𝟐)

11. Taking out a common factor Difference of Two Squares
We will be using TWO of these factorising methods to be able to work out the following without a calculator:
Taking out a common factor
𝒙 𝟐 +𝟑𝒙
×2.5
4.3 2 −1.3×4.3
− 9.7 2 −
Difference of Two Squares
𝒙 𝟐 − 𝒚 𝟐

12. Work out without a calculator: 𝟐.𝟓 𝟐 +𝟎.𝟓×𝟐.𝟓
Take out 2.5 as common (like we do in factorising by common factor)
2.5( )
2.5(3)
2.5×3=7.5

13. Work out without a calculator: 𝟒.𝟑 𝟐 −𝟏.𝟑×𝟒.𝟑
Take out 4.3 as common (like we do in factorising by common factor)
4.3(4.3−1.3)
4.3(3)
4.3×3=12.9

14. Work out without a calculator: 𝟖.𝟕𝟗 𝟐 − 𝟏.𝟐𝟏 𝟐
Difference of Two Squares!
8.79 −
7.58×10
75.8

15. Work out without a calculator: 𝟏𝟎.𝟑 𝟐 − 𝟗.𝟕 𝟐
Difference of Two Squares!
10.3 −
0.6×20 12

16. STP 9 MIXED EXERCISE Factorisng Quadratics HW
Pg 153 Exercise 7k No. 6 ONLY Exercise 7l No. 3 TO No.6