Edexcel IGCSE Maths 复习笔记 2.3.1 Expanding Two Brackets - Basics
What is expanding two brackets?
- When we expand brackets in algebra we ‘get rid of’ the brackets by multiplying out
- When we expand two brackets, each term in one bracket gets multiplied by each term in the other bracket
Beware of minus signs
“ − × − = + ”“ − × + = − ”
How to multiply out two brackets
- Write FOIL above your working spaceF – First term in each bracket
O – Outer pair of termsI – Inner pair of terms
L – Last term in each bracket
- Write down the four multiplications
- Careful here – you have to be sure to include any minus signs!
- Simplify by collecting like terms (if there are any)