The Lesson

An expression is a term or several terms that are added together or subtracted.

Dictionary Definition

The Oxford English Dictionary defines an expression as "a collection of symbols together expressing an algebraical quantity."

Real Examples of Expressions in Algebra

It is easier to understand expressions with examples.
  • An expression can be a single term:

    2 x
  • An expression can several terms that are added together or subtracted:

    2 x + a b c - p (q - r) Each term is separated by an addition (+) or subtaction (-) operator.

From Expressions to Equations

An equation is made when one expression is made equal to another expression.

2 x + a b c = p (q - r) An algebraic equation has one expression either side of an = sign.

Lesson Slides

Expressions in algebra can throw up some complications. The slider below has some more real examples of expressions in algebra.