Expanding expressions

Expanding expressions

Pencil and paper
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Working with Students
Further Resources
This task is about expanding algebraic expressions.
Expand each of the following expressions.
 

a)

2(x + 4) = ____________________
 

b)

6(x – 3) = ____________________
 

c)

⁻2(x + 1) = ____________________
 

d)

⁻3(x – 3) = ____________________
 

e)

(x + 2)(x + 3) = ____________________
 

f)

(x – 2)(x + 4) = ____________________
 

g)

(x – 5)(x – 3) = ____________________

Task administration: 
This task is completed with pencil and paper only.
Level:
5
Description of task: 
Students expand algebraic expressions.
Learning Progression Frameworks
This resource can provide evidence of learning associated with within the Mathematics Learning Progressions Frameworks.
Read more about the Learning Progressions Frameworks.
Answers/responses: 
   

Y10 (11/1999)

a)

2x + 8

easy

b)

6x – 18

easy

c)

⁻2x – 2

moderate

d)

⁻3x + 9

moderate

e)

x2 + 5x + 6 [Accept x2 + 2x + 3x + 6]

easy

f)

x2 + 2x – 8 [Accept x2 – 2x + 4x – 8]

moderate

g)

x2 – 8x + 15 [Accept x2 – 5x – 3x + 15]

moderate

NOTE: Do not accept terms like 2 ?4, x ?x, 2 ?x, + – 2 or – ⁻9, etc.

Diagnostic and formative information: 

  

Student response

Likely reason

e)
f)
g)

x2 + 6
x2 – 8
x2 + 15

Misses out terms in x (the "cross" terms).