Study Notes
In algebra, expansion involves multiplying out brackets to simplify expressions, while factorising is the process of writing expressions as a product of their factors.
- Expansion — multiplying each term inside a bracket by the term outside. Example: (x + 1)(x + 2) becomes x^2 + 3x + 2.
- Factorising — the opposite of expansion, taking out the common factor. Example: 8x^2y + 6xy^2 becomes 2xy(4x + 3y).
- Simplifying — combining like terms in an expression. Example: 3x^2 - x^2 + 2x becomes 2x^2 + 2x.
Exam Tips
Key Definitions to Remember
- Expansion: Multiplying out brackets.
- Factorising: Writing an expression as a product of factors.
- Simplifying: Combining like terms.
Common Confusions
- Forgetting to multiply every term inside the bracket during expansion.
- Not identifying the greatest common factor when factorising.
Typical Exam Questions
- How do you expand (x + 3)(x + 4)? x^2 + 7x + 12
- Factorise 3x^2 + 6x. 3x(x + 2)
- Simplify 2x^2 + 3x - x^2 + 5. x^2 + 3x + 5
What Examiners Usually Test
- Ability to correctly expand and simplify expressions.
- Skill in identifying and factorising common factors.
- Understanding the relationship between expansion and factorisation.