Learning objectives
- Collect like terms and expand brackets.
- Factorise by taking out a common factor.
Key ideas
Like terms have exactly the same letter part, including powers.
Multiply the outside factor by every term in the bracket.
For two brackets, multiply every term in one by every term in the other.
Factorising reverses expansion. Take out the greatest common factor and check by expanding.
Use brackets when substituting a negative number into a power.
Worked examples
Example 1
Expand the bracket and collect like terms.
Example 2
Factorise fully using the greatest common factor.
Watch out
Keep the negative sign when expanding. Unlike terms cannot be combined into a single term.