Difference of Squares Calculator

Factor expressions in the form a² - b² using the difference of squares formula. This calculator shows the step-by-step factorization process and verifies the result.

Formula:

a² - b² = (a + b)(a - b)

Example: 5² - 3² = (5 + 3)(5 - 3) = 8 × 2 = 16

• Works for any real numbers a and b

• Useful for factoring quadratic expressions

• Shows step-by-step factorization process

• Verifies results with expanded form

What is the Difference of Squares?

The difference of squares is a special algebraic pattern where one squared term is subtracted from another. It can always be factored using the formula: a² - b² = (a + b)(a - b).

Formula: a² - b² = (a + b)(a - b)

Example: 16 - 4 = 4² - 2²

= (4 + 2)(4 - 2)

= (6)(2) = 12

Example Problems

Basic Examples

Simple Numbers

  • 9 - 4 = 3² - 2² = (3 + 2)(3 - 2) = 5 × 1 = 5
  • 25 - 16 = 5² - 4² = (5 + 4)(5 - 4) = 9 × 1 = 9
  • 100 - 36 = 10² - 6² = (10 + 6)(10 - 6) = 16 × 4 = 64

With Variables

  • x² - 1 = (x + 1)(x - 1)
  • x² - 4 = (x + 2)(x - 2)
  • x² - 9 = (x + 3)(x - 3)

Real-World Applications

Area Problems

Find the difference in area between two squares:

Large square: 8 × 8 = 64

Small square: 5 × 5 = 25

Difference in area:

64 - 25 = 8² - 5² = (8 + 5)(8 - 5) = 13 × 3 = 39

Number Theory

Use difference of squares to factor numbers:

Factor 399:

Solution:

399 = 400 - 1

= 20² - 1²

= (20 + 1)(20 - 1)

= 21 × 19

Key Points to Remember

  • The formula only works for expressions in the form a² - b²
  • The terms must be perfect squares
  • The middle term must be subtraction (-)
  • The result is always two binomial factors
  • This pattern is one of the standard factoring techniques