unsolvedпричастие прошедшего времени Used as an adjective formed from the past participle of 'solve' with the negating prefix 'un-'.
Переводы
The equation remains unsolved to this day.
L'équation reste non résolue à ce jour.
non élucidéSe dit surtout d’une affaire, d’un crime ou d’un mystère. Not having been solved or resolved. The equation remains unsolved to this day.