AlgebraStudy Notes

Worked Example: Quadratic - Both Positive

Part of FactorisingGCSE Mathematics

This study notes covers Worked Example: Quadratic - Both Positive 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 10 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 10 of 12

Practice

12 questions

Recall

3 flashcards

Worked Example: Quadratic - Both Positive

Factorise: x² + 7x + 12

Step 1 Set up the problem

Need: multiply to 12, add to 7

Step 2 List factor pairs of 12

1 × 12 (sum = 13) ✗

2 × 6 (sum = 8) ✗

3 × 4 (sum = 7) ✓

Final Write the brackets

x² + 7x + 12 = (x + 3)(x + 4)

Check: x² + 4x + 3x + 12 = x² + 7x + 12 ✓

Keep building this topic

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

Practice Questions for Factorising

Which is the correct factorisation of 6x + 15?

  • A. 3(2x + 5)
  • B. 6(x + 9)
  • C. 3(2x + 15)
  • D. 2(3x + 7)
1 markfoundation

A student factorises x² + 5x + 4 as (x + 4)(x + 4). Explain why this is incorrect and give the correct factorisation.

2 marksstandard

Quick Recall Flashcards

Factorising Rule
Find the HCF of all terms (numbers AND letters), put outside bracket, divide each term for inside.
Factorising
Take out highest common factor: 6x + 9 = 3(2x + 3)

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