This document discusses expanding brackets in algebraic expressions. It begins by defining expansion as multiplying an algebraic expression by a term or another algebraic expression. It provides examples of expanding brackets by multiplying each term inside the brackets by the term outside. These include examples of expanding (3x - 4y), (x - y)(3x + 5y), and linear expressions with other linear terms like 5a(4b) and -3m(2m - 7n). The document explains that expanding brackets means multiplying each term inside by the term outside and that the product can be either another term or an algebraic expression.