Factorising expressions II

Factorising expressions II

Pencil and paper
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Working with Students
Further Resources
This task is about factorising algebraic expressions.
Factorise each of the following algebraic expressions:
 
a)
 
4x - 8 = ____________________
 
 
b)
 
6x2- 2x = ____________________
 
 
c)

 
x2 + 5x + 6 = ____________________
 
 
d)

 
x2 - 16 = ____________________
 
 
e)

 
3x2 - 3x - 18 = ____________________
 
 
Task administration: 
This task is completed with pencil and paper only.
Level:
5
Curriculum info: 
Maths, Number and Algebra, Equations and expressions
Keywords: 
algebraic expressions, factorise
Description of task: 
Students factorise algebraic expressions.
Learning Progression Frameworks
This resource can provide evidence of learning associated with
Using symbols and expressions to think mathematically, sets 6-7
within the Mathematics Learning Progressions Frameworks.
Read more about the Learning Progressions Frameworks.
Answers/responses: 
   

Y10 (10/2000)
a) 4(x - 2) moderate
b) 2x(3x - 1) difficult
c) (x + 3)(x + 2) difficult
d) (x + 4)(x - 4) very difficult
e)

Any 1 of:
 
•   3(x +2)(x - 3)
•   (3x + 6)(x - 3)
•   (3x - 9)(x + 2)
•   3(x2 - x - 6)

 very difficult

NOTE: Other equivalent expressions are possible with reversed signs. Accept even if a full factorisation has not been done (e.g., last 3 options in e)).
Diagnostic and formative information: 
  

Common error

Likely reason
a)
b)
c)		 ⁻4x
4x2
6x2+ 6		 Treats 8 as 8x.
Treats 2x as 2x2.
Treats 5x as 5x2.