RocketDigitsStart free

All skills › Year 9 › Patterns & Algebra

Year 9 · Patterns & Algebra

Factorise quadratics

Factorising x² + bx + c means finding two numbers that multiply to c and add to b.

Try a question

Loading a question…

How to do it

  1. List the pairs that multiply to c.
  2. Pick the pair that adds to b.
  3. Write (x + first)(x + second).

Worked example

x² + 5x + 6
2 × 3 = 6 and 2 + 3 = 5
(x + 2)(x + 3)

With a free account, these play as step-by-step animations.

Watch out
Watch the signs: negative c means one positive and one negative number.

Practise Factorise quadratics properly

Ten-question rounds with instant marking, a lesson under every question, stars and badges. Free to start, and the first week includes Premium.

Create a free account

More Patterns & Algebra skills