# How do you find all the zeros of F(x)=x^3 + x^2 +9x + 9?

$- 1 \mathmr{and} \pm 3 i$,
F( x ) = ( x + 1 ) ( ${x}^{2}$+9) = 0
If the sum of the coefficients in F( x ) = 0, ( x$-$1 ) is a factor of F( x ).
If the sum of the coefficients in F($-$ x ) = 0, ( x + 1 ) is a factor.