Skip to main content
  1. Life
  2. Education & Schools
  3. General Education

Binomial facts to memorize

See also

A binomial is a kind of polynomial. "Poly" means many, of which the binomial is one, and "bi-" specifies that this particular polynomial has two terms. There are three expression patterns that occur so often when multiplying binomials that it is helpful to simply memorize them by heart. They are the following expressions:

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

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

(a+b)(a=b) = a^2 - b^2

It is important to keep in mind that the variables a and b need not refer to integers only, but can also refer to variables. Keep in mind to include the middle term 2ab for the first two of the expressions given to memorize. The reason is this: the presence of the middle term 2ab seems quite counterintuitive, and it must be rigorously memorized. For example, our natural inclination for the first two expressions is going to be to forget about the 2ab and write either a^2 + b^2 or a^2 - b^2, but this is incorrect. It is a common error, but in mathematics, a fatal one, and you will get marked wrong if you write it.



  • ESPYS party
    Athletes and celebrities hit the red carpet at Body at the ESPYS party
    Today's Buzz
  • Using metalic paint
    Metallic paint can be used to refinish furniture or to create the illusion of a larger space
    5 Photos
  • Gardening
    Have you ever started a garden and found a lone tomato straggler in with the strawberries?
    7 Photos
  • Adopt a shelter cat
    Ten great reasons to adopt a shelter cat: Just ask Willie Nelson's family
    9 Photos
  • Chikungunya virus
    Health news: Chikungunya virus has hit a man in Florida
    5 Photos
  • Oaks Spa
    Just keep moving is theme at Oaks at Ojai, California’s primo budget spa
    6 Photos