Learn Before
Formula

Perfect Square Trinomials Pattern

The Perfect Square Trinomials Pattern is a factoring shortcut that reverses the Binomial Squares Pattern. Instead of starting with a binomial and squaring it, you start with a trinomial and factor it back into the square of a binomial. If aa and bb are real numbers:

a2+2ab+b2=(a+b)2a^2 + 2ab + b^2 = (a + b)^2

a22ab+b2=(ab)2a^2 - 2ab + b^2 = (a - b)^2

To determine whether a given trinomial fits this pattern, perform three checks:

  1. Is the first term a perfect square a2a^2?
  2. Is the last term a perfect square b2b^2?
  3. Is the middle term equal to 2ab2ab?

If all three conditions hold, the trinomial factors directly into the square of a binomial. The sign of the middle term determines which form to use: a positive middle term means the factored form uses addition, (a+b)2(a + b)^2, while a negative middle term means it uses subtraction, (ab)2(a - b)^2. Although a perfect square trinomial could also be factored using the general methods for trinomials of the form ax2+bx+cax^2 + bx + c, recognizing the perfect square structure and applying this pattern is significantly faster.

0

1

Updated 2026-04-30

Contributors are:

Who are from:

Tags

OpenStax

Elementary Algebra @ OpenStax

Ch.7 Factoring - Elementary Algebra @ OpenStax

Algebra

Math

Ch.8 Rational Expressions and Equations - Elementary Algebra @ OpenStax

Ch.10 Quadratic Equations - Elementary Algebra @ OpenStax

Prealgebra

Intermediate Algebra @ OpenStax

Ch.6 Factoring - Intermediate Algebra @ OpenStax

Related
Learn After