$p,q,r$  are integers such that $f\left(x\right)=x^4+4x^3+6p{x}^2+4qx+r,$  is divisible by $\left(x^3+3x^2+9x+3\right).$  The value of $\left(p+q+r\right)$  is equal to___.

$\left(x^4+4x^3+6p{x}^2+4qx+r\right)=\left(x+a\right)\left(x^3+3x^2+9x+3\right)$

Comparing coefficients $a=1;$ $6p=12$ $\Rightarrow p=2$

                   $4q=12$ $\Rightarrow q=3andr=3$

           Hence $p+q+r=8$