Intractable

непода́тливый

nepodátlivyj

(stubborn, obstinate)

непоко́рный

nepokórnyj

(stubborn, obstinate)

неуправляемый

neupravljajemyj

(not tractable)

тру́дный

trúdnyj

(mathematics: not able to be solved in polynomial time; too difficult to attempt to solve)

трудная

trudnaja

(mathematics: not able to be solved in polynomial time; too difficult to attempt to solve)

трудноизлечи́мый

trudnoizlečímyj

(medicine: difficult to treat)

трудноразрешимый

trudnorazrešimyj

(of a problem: difficult to deal with, solve, or manage)

упря́мый

uprjámyj

(stubborn, obstinate)