Fairly early in your study of algebra, you meet one of the most useful of algebraic techniques, the difference of two squares which enables you to write, for example $x^2-1=(x-1)(x+1)$.
Fairly early in your study of algebra, you meet one of the most useful of algebraic techniques, the difference of two squares which enables you to write, for example $x^2-1=(x-1)(x+1)$.