1 Mathematics a statement that the values of two mathematical expressions are equal (indicated by the sign =).
2 [mass noun] the process of equating one thing with another:the equation of science with objectivity
(the equation) a situation in which several factors must be taken into account:money also came into the equation
3 Chemistry a symbolic representation of the changes which occur in a chemical reaction, expressed in terms of the formulae of the molecules or other species involved.
equation of the first (or second etc.) order
Mathematics an equation involving only the first derivative, second derivative, etc..
