Given:
x3−3x+2
Now if we put x=1 then →(1)3−3(1)+2=0
It's coming zero, it means (x−1) is a factor of x3−3x+2
Now remaining roots we will find by dividing.
x−1)¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯x3−3x+2(x2+x−2x3−x2________x2−3x+2x2−x________−2x+2−2x+2_______0
So, x3−3x+2=(x−1)(x2+x−2)
=(x−1)(x2+2x−x−2)
=(x−1)(x(x+2)−1(x+2))
=(x−1)(x−1)(x+2)
So, x3−3x+2=(x−1)2(x+2)