(х-4)^4-8(х-4)^2-9=0

(Х-4)^4-8(х-4)^2-9=0

(Х-4)^2=t

t^2-8t-9=0

D=64+36=100

t1=(8+10)/2=18/2=9

t2=(8-10)/2=-2/2=-1 неудов.

(Х-4)^2=9

Х-4=3

Х=3+4

Х=7

(Х-4)=-3

Х=-3+4

Х=1