Study Notes
Expansion and factorising involve manipulating algebraic expressions by combining like terms and reversing multiplication.
- Expansion — multiplying out the terms inside a bracket. 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).
- Like Terms — terms in an expression that have the same variables raised to the same power. Example: In 3x^2 + 2x^2, 3x^2 and 2x^2 are like terms.
Exam Tips
Key Definitions to Remember
- Expansion: multiplying terms inside brackets.
- Factorising: taking out the common factor from terms.
- Like Terms: terms with the same variables and powers.
Common Confusions
- Mixing up expansion and factorising.
- Forgetting to combine like terms correctly.
Typical Exam Questions
- How do you expand (x + 1)(x + 2)? x^2 + 3x + 2
- How do you factorise 8x^2y + 6xy^2? 2xy(4x + 3y)
- What are the like terms in 3x^2 + 2x^2? 3x^2 and 2x^2
What Examiners Usually Test
- Ability to expand expressions correctly.
- Skill in factorising expressions by taking out common factors.
- Understanding of combining like terms in simplification.