Welcome to My Bitesize, let's get you set up!

Add your subjects to find the right study guides, track progress and keep everything in one place.

Add my subjects
My Subjects

Algebraic expressions - EdexcelFactorising

Letters can be used to stand for unknown values or values that can change. Formulas can be written and equations solved to find solutions to a range of problems in science and engineering.

Part ofMathsAlgebra

Factorising

Discover the updated revision resources for GCSE Maths: Factorising expressions, with step-by-step slideshows, quizzes, practice exam questions, and more!

Factorising is the opposite process of expanding brackets. A factorised answer will always contain a set of brackets.

To factorise an expression fully, take out the of all the terms. For example, \(2x\) is the HCF of \(4x^2\) and \(6x\) as 2 is the biggest number that will divide into 4 and 6. \(x\) is the biggest term that will divide into \(x^2\) and \(x\).

Example

Factorise \(6x + 9\).

To factorise this expression, look for the HCF of \(6x\) and 9 which is 3. To factorise, write down the HCF and then begin a set of brackets. Find the missing numbers in the brackets by dividing each term by the HCF.

The HCF of \(6x + 9\) is 3. Put this outside the bracket:

\(3(? + ?)\)

Find the missing terms in the bracket by dividing each term by the HCF:

\(6x \div 3 = 2x\) and \(9 \div 3 = 3\)

This gives: \(3(2x + 3)\)

To check this answer is right, expand the bracket and check that the answer matches the original equation:

\(3(2x + 3) = 3 \times 2x + 3 \times 3 = 6x + 9\)

Question

Factorise \(12ab - 8ac + 4a^2b\).