Yes, that seems possible. The Google Books Ngram Viewer doesn't have any hits for "enter the equation". However, the word "equation" and "equations" have the

Yes, that seems possible. The Google Books Ngram Viewer doesn't have any hits for "enter the equation". However, the word "equation" and "equations" have the opposite trend from NYT.[1] But to emphasize again, the hits are less than .01% which is potentially abusing the word "trend". [1]https://books.google.com/ngrams/graph?content=equation%2Cequations%2C+music&year_start=1800&year_end=2000&corpus=15&smoothing=3&share=&direct_url=t1%3B%2Cequation%3B%2Cc0%3B.t1%3B%2Cequations%3B%2Cc0%3B.t1%3B%2Cmusic%3B%2Cc0 https://books.google.com/ngrams/graph?content=equation%2Cequ...