y³-y²-8y+12=0
y³-4y-y²+4y-4-8y+16=0
y*(y²-4)-(y²-4y+4)-8*(y-2)=0
y*(y-2)*(y+2)-(y-2)²-8*(y-2)=0
(y-2)*(y*(y+2)-(y-2)-8=0
y-2=0
y₁=2
y²+2y-y+2-8=0
y²+y-6=0 D=25 √D=5
y₂=2 y₃=-3.
ответ: y₁=2 y₂=-3.
