← Year 9 topics
🧩

Expanding & Factorising

Expanding and factorising are opposites — one opens brackets, the other packs them up.

Expanding single bracketsExpanding double bracketsFactorisingFactorising quadratics

📖 Learn

Double brackets

(x + 3)(x + 5): multiply every term by every term → x² + 8x + 15.

Factorise

Take out the highest common factor: 6x + 9 = 3(2x + 3).

Quadratics

x² + 7x + 12: find two numbers that multiply to 12 and add to 7 → (x + 3)(x + 4).

Worked example

Expand (x + 2)(x + 6)

  1. 1x × x = x²
  2. 2x × 6 + 2 × x = 8x
  3. 32 × 6 = 12 → x² + 8x + 12 ✅

⭐ Practise

π

Ask Professor Pi

Type a question or say where you're stuck. You'll get hints, not just answers!

AI-powered tutor — it can make mistakes, so check with your teacher if unsure.