Olympiad Math Algebric Problem l find all possible solutions of k?

[@vladimirsemenchik2193]

x^2(x-1)=2*2*5*5 --> x=5

[@borisjeud8464]

k=5

[@heribertoayalareyes3628]

Complex = Father. Real and Imaginary = sons

[@heribertoayalareyes3628]

Real and Imaginary are brothers.

[@Марія-75]

Пожалуйста,без музыки, спасибо