(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