This study notes covers Common Mistakes within Factorising for GCSE Mathematics. Revise Factorising in Algebra for GCSE Mathematics with 12 exam-style questions and 3 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 7 of 12 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 12
Practice
12 questions
Recall
3 flashcards
Common Mistakes
✗ 6x + 9 = 3(2x + 9)
✓ 6x + 9 = 3(2x + 3) - divide BOTH terms!
✗ 4x² + 8x = 4(x² + 2x)
✓ 4x² + 8x = 4x(x + 2) - x is also common!
✗ Forgetting to check by expanding
✓ ALWAYS expand to verify your answer!
Practice Questions
Q1 Factorise: 5x + 15 [1 mark]
[1] HCF = 5, so 5(x + 3)
Q2 Factorise: 3x² + 12x [2 marks]
[1] HCF = 3x
[1] 3x(x + 4)
Q3 Factorise: 6x² - 8x [2 marks]
[1] HCF = 2x
[1] 2x(3x - 4)
Q4 Factorise: 10y³ + 5y² - 15y [2 marks]
[1] HCF = 5y
[1] 5y(2y² + y - 3)