Algebraic terms and expressions

In algebra, letters are used to stand for values that can change (variables) or for values that aren’t known (unknowns), for example:

  • \[x\]
  • \[a\]
  • \[h\]

A term is a number or letter on its own, or numbers and letters multiplied together, for example:

  • \[- 2\]
  • \[3x\]
  • \[y^2\]

An expression is a set of terms combined using the operations \(+\), \(-\), \(\times\) or \( \div\), for example:

  • \[4x − 3\]
  • \[5x + 2y\]
  • \[a + 2b + c\]

We can often simplify algebraic expressions so that they are shorter to read and write.

For example, the expression \(b + b + b + b\) can be simplified to \(4b\).

Simplifying an expression like this is called collecting like terms.