х(х-3)(х-2)(х+1)=54,
x(x-2)(x-3)(x+1)=54,
(x^2-2x)(x^2-2x-3)=54,
x^2-2x=a,
a(a-3)=54,
a^2-3a-54=0,
a1=-6, a2=9,
x^2-2x=-6,
x^2-2x+6=0,
D1=-5<0,
x^2-2x=9,
x^2-2x-9=0,
D1=10,
x1=1-√10,
x2=1+√10.
