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 \(m\) and 7 by 3, so: \(3(m + 7) = 3 ...
In algebra, letters are used when numbers are not known. Algebraic terms, such as \(2s\) or \(8y\), leave the multiplication signs out. So rather than \(2 \times s\), write \(2s\), and rather than \(8 ...