Year 10 Interactive Maths - Second Edition

Expressions

To solve a problem we need to find the value of an unknown quantity or quantities.  The unknown quantity or quantities are represented by letters that are known as pronumerals.

An expression is a combination of mathematical terms using operations such as addition, subtraction, multiplication, division, brackets, powers or roots.  

For example, 2x + 3y is an expression involving addition where 2x and 3y are called the terms of the expression.  Terms often include pronumerals but may also be a number called a constant term.

Terms with the same pronumeral or pronumerals are called like terms.

Terms that do not have the same pronumerals are called unlike terms.

Addition and Subtraction

Only like terms can be added (or subtracted) to simplify an expression involving addition (or subtraction).

Example 1

Solution:

Key Terms

pronumerals, expression, terms, constant term, like terms, unlike terms