Expand Polynomial Calculator

This expand polynomial calculator multiplies out brackets and sorts the result by power. (2x+3)(x−4) becomes 2x² − 5x − 12, with every intermediate step and a note on special product formulas.

Source: Wikipedia – Distributivgesetz. Updated: .

e.g. (2x+3)(x-4), (a+b)^2 or 3x(x-4); letters are variables
My ToolboxYour inputs are saved in this browser only.

Result

Expanded
2x² − 5x − 12
Working
  • (2x + 3) · (x − 4) = 2x² − 5x − 12

How it is calculated

Expanding means multiplying every term in one bracket by every term in the other, then collecting like terms. The basis is the distributive law a(b + c) = ab + ac.

How the calculator works

For (2x+3)(x−4) the four products are 2x · x = 2x², 2x · (−4) = −8x, 3 · x = 3x and 3 · (−4) = −12. Collecting −8x + 3x = −5x gives 2x² − 5x − 12. With more than two factors the working shows how the product is built from left to right, one factor at a time. Powers such as (x+1)³ are expanded as repeated multiplication. For two binomials this is the FOIL method: first, outer, inner, last.

Special product formulas

The calculator recognises the three patterns (a + b)², (a − b)² and (a + b)(a − b) and names a and b. They save work: (x+5)² is x² + 10x + 25, and (x+5)(x−5) is x² − 25 with no middle term.

Frequently asked questions

How do you multiply out two brackets?

Multiply each term of the first bracket by each term of the second and collect like terms. (x+2)(x+3) becomes x² + 3x + 2x + 6 = x² + 5x + 6.

What are the three special product formulas?

(a + b)² = a² + 2ab + b², (a − b)² = a² − 2ab + b² and (a + b)(a − b) = a² − b². The calculator names the matching formula whenever the expression has that shape.

Can I use several variables?

Yes. Each letter is its own variable. (a+b)(a−c) gives a² − ac + ab − bc, ordered by degree.

Sources and legal basis

As of: · Editorial policy

Related tools