What does equation mean?
An equation is a mathematical statement declaring that two expressions have the same value, usually written with an equals sign and often containing one or more unknown quantities called variables. Solving an equation means finding the values that make the statement true — a task central to algebra, physics, engineering, economics, and virtually every quantitative field. Beyond its technical sense, the word has rich figurative uses: people speak of 'balancing the equation,' adding 'another variable to the equation,' or criticizing 'the false equation of money with success.' In these everyday senses, an equation represents any situation whose parts must be weighed together to reach an outcome. Derived from Latin roots meaning 'to make equal,' the word entered English in the early modern period alongside the rise of symbolic algebra. It remains indispensable both as a precise tool of science and as a flexible metaphor for weighing competing factors in complex decisions.
A mathematical statement asserting that two expressions are equal, usually containing one or more variables whose values satisfy the statement.
"To find the break-even point, the accountant set up a simple linear equation."
Distinguished from an expression (which has no equals sign) and an inequality (which uses symbols like < or >).
The act or process of equating one thing with another; a considered equivalence between two different concepts or factors.
"The author challenged the common equation of intelligence with academic success."
A set of circumstances, considerations, or factors that together determine an outcome.
"Rising fuel costs added a new element to the company's budgetary equation."
Regular plural; used freely when referring to multiple mathematical statements or figurative sets of factors.
"The textbook contains hundreds of practice equations for students to solve."
Every time you write 'x', you're doing what Persian mathematician al-Khwarizmi helped invent over a thousand years ago — turning unknowns into something you can solve.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of equation
The word 'equation' derives from the Latin 'aequatio,' meaning 'an equalizing,' itself from 'aequare' — 'to make equal' — built on 'aequus,' meaning 'level' or 'fair.' This same Latin root gives English a family of related words including 'equal,' 'equate,' 'adequate,' and 'equator.' The term was adopted into English in the late Middle Ages and became established in its modern mathematical sense during the sixteenth and seventeenth centuries, as symbolic algebra developed through the work of European mathematicians such as Viète and Descartes.
How equation is actually used
In mathematical contexts, 'equation' is precise and technical. In figurative use, it often appears in phrases like 'part of the equation' or 'changes the equation,' meaning a factor or consideration in a broader situation. The verb 'equate' and noun 'equation' both carry the figurative sense of treating unlike things as equivalent, sometimes with a negative connotation when criticized ('a false equation').
Easily confused with equation
An equality is a general statement that two things are equal, while an equation is specifically a mathematical statement, often with variables to solve for.
A formula expresses a general rule for computing a result, whereas an equation states that two expressions are equal and may require solving.