Question

x(x2-1)-2x-2 is the polynomial find it's zero

Answer 1

x(x2-1)-2x-2
x3-x-2x-2=0
x3-3x-2=0
putting -1 as x
P(-1)=(-1)3-3(-1)-2
=-1+3-2
=0
That means -1 is a factor
x=-1
x+1=0
Dividing x+1 by x3-3x-2
The qutiont will be x2-x-2
Factor of the polynomial
x2-2x+x-2=0
x(x-2)+1(x-2)=0
(x-2) , (x+1) ,(x+1). There are two x+1 as we have divided the polynomial by x+1 therefore there are two x+1 factors
x=2, x=-1 x=-1
That's your answer