Editing Expression (mathematics) (section)

===Polynomial expression===

A [[polynomial expression]] is an expression built with [[scalar (mathematics)|scalar]]s (numbers of elements of some field), [[indeterminate (variable)|indeterminate]]s, and the operators of addition, multiplication, and exponentiation to nonnegative integer powers; for example <math>3(x+1)^2 - xy.</math>

Using [[associativity]], [[commutativity]] and [[distributivity]], every polynomial expression is equivalent to a [[polynomial]], that is an expression that is a [[linear combination]] of products of integer powers of the indeterminates. For example the above polynomial expression is equivalent (denote the same polynomial as <math>3x^2-xy+6x+3.</math>

Many author do not distinguish polynomials and polynomial expressions. In this case the expression of a polynomial expression as a linear combination is called the ''canonical form'', ''normal form'', or ''expanded form'' of the polynomial.