<PRE><B>Question 155829</B>
x^3 + 4x^2 - x - 4=0 has a root 1
then

     1     4     -1   -4
1          1      5    4
     1     5      4    0
(click on show source code to understand it)

Q(x)=x^2+5x+4=0
then
{{{x = (-5 +- sqrt( 5^2-4*(1)*(4) ))/(2*(1)) }}}
={{{x = (-5 +- 3 )/2 }}}
so roots of Q(x) are -4 and -1
then
roots of P(x)=x^3 + 4x^2 - x - 4
are 1,-1 and -4

P(x)=(x-1)(x+1)(x+4)

{{{ graph( 300, 200, -8, 5, -20, 20, x^3 + 4x^2 - x - 4) }}}


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