Factorising into a single bracket
The Maths Habit
1Expand 2(x + 6)
2x + 12
2Expand 5(x − 2)
5x − 10
312 ÷ 3
4
Sam packs all of this into party bags. Every bag is the same. Every bag gets one cake. How many bags? What goes in each bag?
3 bags. A cake and 2 sweets in each bag.
- Term
- One part of an expression. Terms are joined by + or − signs.
- Common factor
- A number that goes into every term.
- Factorise
- Write an expression with a bracket. It is the opposite of expand.
Factorise 3x + 6
3 x bars and 6 squares
×3x+61Find the common factor
3One x bar in each row: 3 rows.
2Divide each part
x+2Each row is x + 2.
Answer3(x + 2)
Write the expression for these tiles.
2x + 10
Which is right?
3x + 213(x + 21)3(x + 7)
3(x + 7): divide each part
Factorise 4x + 20
2Divide each part
×x+51Find the common factor
44x+20Answer4(x + 5)
Factorise 2x + 6
2Divide each part
×x+31Find the common factor
22x+6Answer2(x + 3)
Factorise 4x + 20
2Divide each part
×x+51Find the common factor
44x+20Answer4(x + 5)
Factorise 5x + 30
2Divide each part
×x+61Find the common factor
55x+30Answer5(x + 6)
Remember1Find the common factor2Divide each part
Factorise 4x + 20
2Divide each part
×x+51Find the common factor
44x+20Answer4(x + 5)
Factorise 2x + 14
2Divide each part
×x+71Find the common factor
22x+14Answer2(x + 7)
Remember1Find the common factor2Divide each part
Factorise 4x + 20
2Divide each part
×x+51Find the common factor
44x+20Answer4(x + 5)
Factorise 4x + 16
2Divide each part
×x+41Find the common factor
44x+16Answer4(x + 4)
Remember1Find the common factor2Divide each part
Factorise 2x + 18
Answer2(x + 9)
Factorise 3x + 18
Answer3(x + 6)
Factorise 5x + 25
Answer5(x + 5)
Remember1Find the common factor2Divide each part
- A dashed square takes away 1.
- 4x − 12 is 4 rows of x − 3.
- Keep the − with the 3 on top of the grid: −3.
What goes on top of the grid?
3x − 9
x and −3
Factorise 4x − 12
2Divide each part
×x−31Find the common factor
44x−12Answer4(x − 3)
Factorise 2x − 8
2Divide each part
×x−41Find the common factor
22x−8Answer2(x − 4)
Factorise 4x − 12
2Divide each part
×x−31Find the common factor
44x−12Answer4(x − 3)
Factorise 5x − 15
2Divide each part
×x−31Find the common factor
55x−15Answer5(x − 3)
Remember1Find the common factor2Divide each part
Factorise 4x − 12
2Divide each part
×x−31Find the common factor
44x−12Answer4(x − 3)
Factorise 3x − 15
2Divide each part
×x−51Find the common factor
33x−15Answer3(x − 5)
Remember1Find the common factor2Divide each part
Factorise 4x − 12
2Divide each part
×x−31Find the common factor
44x−12Answer4(x − 3)
Factorise 4x − 20
2Divide each part
×x−51Find the common factor
44x−20Answer4(x − 5)
Remember1Find the common factor2Divide each part
Factorise 2x − 14
Answer2(x − 7)
Factorise 5x − 20
Answer5(x − 4)
Factorise 3x − 18
Answer3(x − 6)
Remember1Find the common factor2Divide each part
Is it factorised right? Thumbs up: yes. Thumbs down: no.
2x + 16 = 2(x + 8)
Yes
5x + 35 = 5(x + 35)
No: 5(x + 7)
4x − 24 = 4(x + 6)
No: 4(x − 6)
10x + 20 = 10(x + 2)
Yes
3x − 27 = 3(x − 9)
Yes
Find the missing number. 6x + 30 = 6(x + □)
5
Factorise 6x + 9. Hint: 3 goes into both.
3(2x + 3)
Dan factorises 12x + 8 as 2(6x + 4). Dan has not finished. Finish it.
4(3x + 2)
Factorise 2x + 12. Step 1 is given: the common factor is 2.
Answer 2(x + 6)
Factorise 5x − 25
Answer 5(x − 5)
Factorise 10x + 40
Answer 10(x + 4)
Exit tickets to print