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Greek Gymnasium Grade 3 / Mathematics / Two-unit revision pilot

Algebraic expressions

Algebraic expressions: structured theory, worked examples, answered practice, and a mastery checklist for Greek Gymnasium Grade 3.

CHAPTER PLAN

Learn, practise, and check your progress

Follow the steps in order or jump directly to the part you need.

—/5

completed

Estimated active study time

156 minutes

  1. 1. Understand

    Objectives, key ideas, and structured theory.

    Open →
  2. 2. Follow the method

    Worked examples that explain every step.

    Open →
  3. 3. Practise

    Graded tasks with hints and answer guidance.

    Open →
  4. 4. Consolidate

    Assignments from core work to challenge.

    Open →
  5. 5. Check

    A timed, marked test with solution guidance.

    Open →

Progress is stored only in this browser and does not require AI credits.

Learning objectives

  • ✓I can explain and apply: Distributivity and identities.
  • ✓I can explain and apply: Factorisation.
  • ✓I can explain and apply: Restrictions on rational expressions.

Key ideas and checks

  • (x±a)²=x²±2ax+a².
  • x²−a²=(x−a)(x+a).
  • Cancel factors, not terms in sums.

Unit

Core theory

The essential chapter ideas in a clear sequence before practice.

01

Understanding the concept

Under distributivity, multiply every term of the first bracket by every term of the second. Collect only like terms: x and x² are not terms of the same kind.

02

Method and conditions

Factorisation writes a sum as a product. Check for a common factor before using an identity. Expanding the product must reproduce the original expression exactly.

03

Checking and coverage boundaries

For a rational expression, record where the original denominator is zero before simplifying. Cancelling a common factor does not restore excluded values. For example, (x²−9)/(x−3)=x+3 holds only for x≠3.

04

Original pilot material — human educator review pending

Written specifically for YourFavTeacher with AI assistance, without copying past-paper prompts. Technical and numerical checks do not replace review by a human educator. It is not an official paper or endorsed by an examination body.

Mathematics

Worked examples

Follow the method step by step and check why every step is valid.

Worked example 1

Expand and simplify (6x+2)(x−5).

  1. 1Multiply every term in the first bracket by every term in the second.
  2. 26x²−30x+2x−10
  3. 3At x=0 both forms give −10.

6x²-28x−10

Worked example 2

Simplify (x²−25)/(x−5) and state the restriction.

  1. 1The original denominator requires x≠5.
  2. 2x²−25=(x−5)(x+5)
  3. 3Cancel the common factor only for x≠5.

x+5, x≠5

Worked example 3

Simplify 6(x+2)−5(x−1).

  1. 1Watch the negative sign before the second bracket.
  2. 26x+12−5x+5
  3. 3The coefficient of x is 6−5=1.

x+17

Algebraic expressions

Practice with answers

Eight graded tasks from core fluency to exam-style application. Work independently before opening a hint or answer.

Core fluency6 minutes

Expand and simplify (3x+2)(x−2).

Hint

Multiply every term in the first bracket by every term in the second.

Answer guide

Multiply every term in the first bracket by every term in the second. 3x²−6x+2x−4 At x=0 both forms give −4. 3x²-4x−4

Core fluency6 minutes

Expand (x+3)² and explain the middle term.

Hint

A square is a product of two identical brackets.

Answer guide

A square is a product of two identical brackets. (x+3)(x+3)=x²+3x+3x+9 The two cross terms add; they must not be omitted. x²+6x+9

Core fluency6 minutes

Factor x²−9.

Hint

Recognise a difference of two squares.

Answer guide

Recognise a difference of two squares. x²−3²=(x−3)(x+3) Expanding makes the cross terms cancel. (x−3)(x+3)

Application6 minutes

Factor 3x²+6x.

Hint

Both terms have a common factor.

Answer guide

Both terms have a common factor. 3x²+6x=3x(x+2) Expand to check both original terms. 3x(x+2)

Application6 minutes

Simplify (x²−4)/(x−2) and state the restriction.

Hint

The original denominator requires x≠2.

Answer guide

The original denominator requires x≠2. x²−4=(x−2)(x+2) Cancel the common factor only for x≠2. x+2, x≠2

Application6 minutes

Calculate (3x²)·(−2x³).

Hint

Multiply coefficients and add exponents of the same base.

Answer guide

Multiply coefficients and add exponents of the same base. 3·(−2)=−6; x²·x³=x⁵ The sign is negative, not positive. −6x⁵

Reasoning6 minutes

Someone writes (x−2)²=x²−4. Identify the error by expanding.

Hint

(x−2)(x−2)=x²−2x−2x+4

Answer guide

(x−2)(x−2)=x²−2x−2x+4 There is a middle term and the constant term is positive. At x=0 the square is 4, not −4. x²−4x+4

Reasoning6 minutes

Simplify 3(x+2)−2(x−1).

Hint

Watch the negative sign before the second bracket.

Answer guide

Watch the negative sign before the second bracket. 3x+6−2x+2 The coefficient of x is 3−2=1. x+8

Common mistakes

  • Omitting the middle term in a squared binomial.
  • Cancelling individual terms inside a sum.
  • Losing the original denominator restriction.

Mastery check

  • ✓I can solve independently and check: Distributivity and identities.
  • ✓I can solve independently and check: Factorisation.
  • ✓I can solve independently and check: Restrictions on rational expressions.

Algebraic expressions

Chapter homework

Six distinct assignments from core fluency to challenge, each with an estimated time, hint, and answer guide.

Core8 minutes

Expand and simplify (4x+2)(x−3).

Hint

Multiply every term in the first bracket by every term in the second.

Answer guide

Multiply every term in the first bracket by every term in the second. 4x²−12x+2x−6 At x=0 both forms give −6. 4x²-10x−6

Core8 minutes

Expand (x+4)² and explain the middle term.

Hint

A square is a product of two identical brackets.

Answer guide

A square is a product of two identical brackets. (x+4)(x+4)=x²+4x+4x+16 The two cross terms add; they must not be omitted. x²+8x+16

Stretch8 minutes

Factor x²−16.

Hint

Recognise a difference of two squares.

Answer guide

Recognise a difference of two squares. x²−4²=(x−4)(x+4) Expanding makes the cross terms cancel. (x−4)(x+4)

Stretch8 minutes

Factor 4x²+12x.

Hint

Both terms have a common factor.

Answer guide

Both terms have a common factor. 4x²+12x=4x(x+3) Expand to check both original terms. 4x(x+3)

Challenge8 minutes

Simplify (x²−9)/(x−3) and state the restriction.

Hint

The original denominator requires x≠3.

Answer guide

The original denominator requires x≠3. x²−9=(x−3)(x+3) Cancel the common factor only for x≠3. x+3, x≠3

Challenge8 minutes

Calculate (4x²)·(−3x³).

Hint

Multiply coefficients and add exponents of the same base.

Answer guide

Multiply coefficients and add exponents of the same base. 4·(−3)=−12; x²·x³=x⁵ The sign is negative, not positive. −12x⁵

45 minutes / 40 marks

Full chapter test

A timed, full-mark self-assessment with model-answer guidance.

Test timer

Ready to start

Time remaining: 45:00

Show working, units and a final check. Equivalent correct methods are accepted. Timing is a revision guide, not official examination conditions.

1. Expand and simplify (5x+2)(x−4).

5 marks
Answer guide

Multiply every term in the first bracket by every term in the second. 5x²−20x+2x−8 At x=0 both forms give −8. 5x²-18x−8

2. Expand (x+5)² and explain the middle term.

5 marks
Answer guide

A square is a product of two identical brackets. (x+5)(x+5)=x²+5x+5x+25 The two cross terms add; they must not be omitted. x²+10x+25

3. Factor x²−25.

5 marks
Answer guide

Recognise a difference of two squares. x²−5²=(x−5)(x+5) Expanding makes the cross terms cancel. (x−5)(x+5)

4. Factor 5x²+20x.

5 marks
Answer guide

Both terms have a common factor. 5x²+20x=5x(x+4) Expand to check both original terms. 5x(x+4)

5. Simplify (x²−16)/(x−4) and state the restriction.

5 marks
Answer guide

The original denominator requires x≠4. x²−16=(x−4)(x+4) Cancel the common factor only for x≠4. x+4, x≠4

6. Calculate (5x²)·(−4x³).

5 marks
Answer guide

Multiply coefficients and add exponents of the same base. 5·(−4)=−20; x²·x³=x⁵ The sign is negative, not positive. −20x⁵

7. Someone writes (x−4)²=x²−16. Identify the error by expanding.

5 marks
Answer guide

(x−4)(x−4)=x²−4x−4x+16 There is a middle term and the constant term is positive. At x=0 the square is 16, not −16. x²−8x+16

8. Simplify 5(x+2)−4(x−1).

5 marks
Answer guide

Watch the negative sign before the second bracket. 5x+10−4x+4 The coefficient of x is 5−4=1. x+14

Unit

Official sources and verification

Curriculum reference sources. Always confirm the teaching sequence with the school and tutor.

Digital School — Mathematics, Gymnasium Grade 3Official reference for level and topic checking, not a source of copied questions or evidence of endorsement. The assessment covers only the listed subtopics.

Mathematics

A bridge year into Lyceum: students need confidence in algebraic manipulation and basic proof thinking.

Back to subject

What this chapter covers

The structure follows the official textbook layout and is used to organise study.

Distributivity and identities
Factorisation
Restrictions on rational expressions

Where to focus

The areas that usually create mistakes or need extra revision.

I can solve independently and check: Distributivity and identities.
I can solve independently and check: Factorisation.
I can solve independently and check: Restrictions on rational expressions.

Sources, daily material, and resources

Where to start: textbook, daily material, PDFs, videos, and worked examples.

Start from the official textbook or specification referenced on the subject page.
Use the notes and examples as support, not as a replacement for the official syllabus.
Check the current syllabus version before exam preparation.

Practice by subtopic

Targeted practice before full tests so coverage is clear.

Expand and simplify (3x+2)(x−2).
Expand (x+3)² and explain the middle term.
Factor x²−9.
Factor 3x²+6x.
Simplify (x²−4)/(x−2) and state the restriction.
Calculate (3x²)·(−2x³).
Someone writes (x−2)²=x²−4. Identify the error by expanding.
Simplify 3(x+2)−2(x−1).

Mocks and progress checks

How to measure progress in this chapter and when it enters a cumulative mock.

Start with untimed practice by subtopic.
Move to a short timed checkpoint only after completing the mastery checklist.
Record each error with the correct method and revisit it after 48 hours.

Next step

What to do after finishing the chapter and how it connects to the next unit.

Complete the practice without support.
Explain the core method aloud in under two minutes.
Continue to the next chapter or request targeted tutor support.

Note: for the official examinable syllabus of each school year, always confirm with the school, tutor, and current Ministry/IEP announcements.

Chapter 1 of 7

Next chapter →Εξισώσεις και ανισώσεις
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