How do you find that: $x^3+4x^2+x-6=(x+2)(x^2+2x-3)$? How do you find that: $x^3+4x^2+x-6=(x+2)(x^2+2x-3)$?
I get that you can take out the $x$ like so: $x^3+4x^2+x-6=x(x^2+4x+1)-6$ but how do you get the $2$ from here?

I think it may be done the folowing way:
$x^3+4x^2+x−6=x^3+2x^2+2x^2+4x-3x-6=x^2(x+2) + 2x(x+2)-3(x+2)=(x+2)(x^2+2x-3)$
