Algebra 1 · Factoring

Difference of Squares

Algebra 1 · Factoring

Definition

A difference of squares is a binomial a^2 - b^2 that factors as (a + b)(a - b).

Examples

  • x^2 - 16 = (x + 4)(x - 4).
  • x^2 - 25 = (x + 5)(x - 5).

Key rule

Factor a^2 - b^2 into conjugate binomials.

Memory hook

Difference of squares splits into plus and minus twins.