Answer:
x=2 is not a solution
Explanation:
x^4 +2x^3 -x^2 -2x = 0
I will factor by grouping
x^4 -x^2 + 2x^3 -2x =0
Factor out x^2 from the first group and 2x from the second group
x^2(x^2-1) +2x(x^2-1) =0
Now factor out x^2-1
(x^2-1) (x^2+2x)=0
From the second term we can factor out an x
(x^2-1) x(x+2)=0
Using the zero product property
(x^2-1) =0 x = 0 (x+2)=0
x^2 =1 x=0 x=-2
Taking the square root
x=±1 x=0 x= -2
The solutions are -2,-1,0,1