# Math Help - factoring a quadrinomial

Hi,

I'm trying to factor $-x^3+3x+2$ so I can find the zeros (well its actually part of a linear algebra prob. for which I need to find the eigenvalues) but I can't figure out how to factor it... even after consulting tutorial sites to dust off my factoring skills :S...

Help?

2. -x^3+3x+2=-x^3+x+2x+2=-x(x^2-1)+2(x+1)=-x(x-1)(x+1)+2(x+1)=
(x+1)[-x(x-1)+2]=(x+1)(-x^2+x+2)

-x^2+x+2=0
D=1+8=9
x1=-1
x2=2
-x^2+x+2=-(x+1)(x-2)

(x+1)(-x^2+x+2)=-(x+1)(x+1)(x-2)=-(x+1)^2(x-2)