x^5-10x^3+9x
x(x^4-10x^2+9)
x(x^4-x^2-9x^2+9)
x[x^2(x^2-1)-9(x^2-1)]
x(x^2-1)(x^2-9)
x(x-1)(x+1)(x-3)(x+3)
Notam x=3k
3k(3k-1)(3k+1)(3k-3)(3k+3)
3k(3k-1)(3k+1)3(K-1)3(K+1)
27k(3k-1)(3k+1)(K-1)(K+1) divizibil cu 27
(X-2)(x+2)x(x-1)(x+1)(x-2)(x+2)
Observam ca avem 4 numere consecutive x(x+1)(x+2)(x+3)
840=4*5*6*7
