Question

X^5+x^4-6x^3-6x^2+5x+5=0

Answer 1

Метод группировки

Х^4(х+1)-6х^2(х+1)+5(х+1)=0

(х+1)(х^4-6х^2+5)=0

Х+1=0       х^4-6х^2+5=0

Х=-1         х^2=t

                t^2-6t+5=0

                t=5                 t=1

               x^2=5             x^2=1

               x=+корень5   х=±1