AlgebraStudy Notes

Common Mistakes

Part of Expanding Brackets · GCSE GCSE Mathematics revision

This study notes covers Common Mistakes within Expanding Brackets for GCSE Mathematics. Revise Expanding Brackets in Algebra for GCSE Mathematics with 14 exam-style questions and 3 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 7 of 13 in this topic. Use this study notes to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 7 of 13

Practice

14 questions

Recall

3 flashcards

Common Mistakes

✗ 3(x + 4) = 3x + 4 ✓ 3(x + 4) = 3x + 12 (multiply BOTH terms)

✗ -2(x - 3) = -2x - 6 ✓ -2(x - 3) = -2x + 6 (neg × neg = pos)

✗ 5(x + 2) = 5x + 2 ✓ 5(x + 2) = 5x + 10 (don't forget the second term!)

Practice Questions

Q1 Expand: 2(x + 4) [1 mark]

[1] 2 × x + 2 × 4 = 2x + 8

Q2 Expand: 5(3x - 7) [2 marks]

[1] 5 × 3x = 15x

[1] 5 × (-7) = -35

Answer: 15x - 35

Q3 Expand: -4(x - 3) [2 marks]

[1] -4 × x = -4x

[1] -4 × (-3) = +12

Answer: -4x + 12

Q4 Expand: 3x(2x + 5) [2 marks]

[1] 3x × 2x = 6x²

[1] 3x × 5 = 15x

Answer: 6x² + 15x

Keep building this topic

Read this section alongside the surrounding pages in Expanding Brackets. That gives you the full topic sequence instead of a single isolated revision point.

Worked Example 3: Negative Outside Advanced: Double Brackets What Does "Expand" Mean?The Key Rule

Practice Questions for Expanding Brackets

Which expression is equivalent to 3(x + 2)?

A. 3x + 2
B. x + 6
C. 3x + 6
D. 3x + 5

1 markfoundation

Expand -2(3x - 5)

2 marksfoundation

Quick Recall Flashcards

Sign Rules

Positive × Positive = Positive | Negative × Negative = Positive | Different signs = Negative

Expansion Rule

a(b + c) = ab + ac - multiply EVERY term inside by the term outside

14 questions on Expanding Brackets — practise free

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Worked Example 3: Negative Outside

Advanced: Double Brackets