You can put this solution on YOUR website! First factor out -2x
-2x*(4x^3+12x^2+9x+2)
then we check for possible factors
4*2=8
-8-1
-4-2
1 8
4 2
Not too many to try
-2x *(x+2)*(4x^2+4x+1)
4*(x^2+x+1/4)
1/4
factors are
1 and 1/4
1/2 and 1/2
-1/2 -1/2
-1 -1/4
4*(x+1/2)^2
(2(x+1/2))^2
or (2x+1)^2
-2x *(x+2)*(2x+1)^2