To factor $ x^{3}+x^{2}+9x+9 $ we can use factoring by grouping:
Group $ \color{blue}{ x^{3} }$ with $ \color{blue}{ x^{2} }$ and $ \color{red}{ 9x }$ with $ \color{red}{ 9 }$ then factor each group.
$$ \begin{aligned} x^{3}+x^{2}+9x+9 = ( \color{blue}{ x^{3}+x^{2} } ) + ( \color{red}{ 9x+9 }) &= \\ &= \color{blue}{ x^{2}( x+1 )} + \color{red}{ 9( x+1 ) } = \\ &= (x^{2}+9)(x+1) \end{aligned} $$