35a + 28 18b2 – 10b 9(3c + 2) 3d(5d + 4) 12e2f – 8ef2 5gh(7g – 5h)

To be able to factorise we must ask 1. What’s common amongst the terms? Put what’s common outside the brackets 2. What’s left after taking out the common? We put what’s left inside the brackets Let’s look at an example!

Factorised answer: 5a(2a + 3) How can we write 10a2 as a product of factors? 10a2 = 2 x 5 x a x a How can we write 15a as a product of factors? 15a = 3 x 5 x a What’s common? 5a What’s left? 2a + 3 Factorised answer: 5a(2a + 3)

Factorised answer: 6b(3b - 2) How can we write 18b2 as a product of factors? 18b2 = 2 x 3 x 3 x b x b How can we write 12b as a product of factors? 12b = 2 x 3 x 2 x b What’s common? 6b What’s left? 3b - 2 Factorised answer: 6b(3b - 2)

Factorised answer: 7ab(3b – 4a) How can we write 21ab2 as a product of factors? 21ab2 = 7 x 3 x a x b x b How can we write 28a2b as a product of factors? 28a2b = 2 x 2 x 7 x a x a x b What’s common? 7ab What’s left? 3b – 4a Factorised answer: 7ab(3b – 4a)

Factorise: 𝟏𝟖𝒂𝒃+𝟗𝒂 𝟗𝒂(𝟐𝒃+𝟏)

Factorise: 𝟔𝒂𝒄+𝟏𝟖𝒂𝒃−𝟏𝟐𝒂𝒅 𝟔𝒂(𝒄+𝟑𝒃−𝟐𝒅)

Classwork/Homework Pg 142 – Pg 143 Exercise 7a 12,18 21,27 34,37

CW/HW Check 12.) 𝒂 𝟐 +𝟔𝒂 What’s common? 𝒂 What’s left? 𝒂+𝟔 Answer: 𝒂(𝒂+𝟔)

CW/HW Check 18.) 𝟒𝒂 𝟐 −𝒂 What’s common? 𝒂 What’s left? 𝟒𝒂−𝟏 Answer: 𝒂(𝟒𝒂−𝟏)

CW/HW Check 21.) 𝟐𝟓𝒂 𝟐 −𝟓𝒂 What’s common? 𝟓𝒂 What’s left? 𝟓𝒂−𝟏 Answer: 𝟓𝒂(𝟓𝒂−𝟏)

CW/HW Check 27.) 𝟗𝒚 𝟐 −𝟔𝒚 What’s common? 𝟑𝒚 What’s left? 𝟑𝒚−𝟐 Answer: 𝟑𝐲(𝟑𝒚−𝟐)

CW/HW Check 34.) 𝟒 𝒂 𝟐 +𝟖𝒂−𝟒 What’s common? 𝟒 What’s left? 𝒂 𝟐 +𝟐𝒂−𝟏 Answer: 𝟒( 𝒂 𝟐 +𝟐𝒂−𝟏)

CW/HW Check 37.) 𝟐𝒙𝒚−𝟒𝒚𝒛+𝟖𝒚𝒘 What’s common? 𝟐𝒚 What’s left? 𝒙−𝟐𝒛+𝟒𝒘 Answer: 𝟐𝒚(𝒙−𝟐𝒛+𝟒𝒘)

TAKE OUT THE COMMON FACTORS! Factorising TAKE OUT THE COMMON FACTORS!

Groups of 4 SET 1 ) 5𝑎𝑏−10𝑏𝑐 ) 2 𝑎 2 −12𝑎 SET 2 ) 2 𝑧 3 +4𝑧 ) 6 𝑝 2 +2𝑝 SET 2 ) 2 𝑥 2 +4𝑥+6 ) 𝑎𝑏+4𝑏𝑐−3𝑏𝑑 ) 9𝑎𝑏−6𝑎𝑐−3𝑎𝑑 ) 5𝑎𝑏+10𝑏𝑐+5𝑏𝑑

Making Questions You will do this in pairs Without the other person seeing write two expressions to expand Still without them seeing expand and simplify those brackets Swap books and write the expanded expressions down in their books They must factorise the expressions you wrote Swap, Mark and Discuss

Homework STP 9 Pg 143 Exercise 7a 50-57