The order to try (every time)
A standard method from Polynomials and factorisation: the steps.
Steps
- Common factor first. Take out the H.C.F. of all terms, including a negative sign if the first term is negative.
- Count the terms:
- 2 terms: is it a difference of two squares, a² − b²?
- 3 terms: is it a perfect square? If not, use the cross-method.
- 4 terms: group into pairs, factorise each pair, then take out the common bracket.
- Check each bracket to see if it can be factorised again.
For the whole topic, read Polynomials and factorisation: key points, common mistakes and how the DSE tests it.