1 Addition and subtraction of like terms

2 Removing brackets from expressions $a\left(b+c\right)$ and $a\left(b-c\right)$

3 Removing brackets from expressions of the form $\left(a+b\right)\left(c+d\right)$

4 Engineering Example 1

  4.1 Reliability in a communication network

5 Factorisation

6 Factorising quadratic expressions

  6.1 Case 1

  6.2 Case 2