In order to expand and simplify an expression, we need to multiply out the brackets and then simplify the resulting expression by collecting the like terms. Expanding brackets (or multiplying out) is the process by which we remove brackets. It is the reverse process of factorisation.
What does it mean to expand an equation?
To expand a bracket means to multiply each term in the bracket by the expression outside the bracket. For example, in the expression 3 ( m + 7 ) , multiply both and 7 by 3, so: 3 ( m + 7 ) = 3 × m + 3 × 7 = 3 m + 21 .