equation vs matching

equation

noun
  • The act or process of equating two or more things, or the state of those things being equal (that is, identical). 

  • An assertion that two expressions are equal, expressed by writing the two expressions separated by an equal sign; from which one is to determine a particular quantity. 

  • A small correction to observed values to remove the effects of systematic errors in an observation. 

matching

noun
  • The process by which things are matched together or paired up. 

  • A set of independent edges in a given graph, i.e. a set of edges which do not intersect, such that pairs of vertices are "matched" to each other one to one. 

adj
  • The same as another; sharing the same design. 

How often have the words equation and matching occurred in a corpus of books? (source: Google Ngram Viewer )