9: \(=x^2\left(x+2\right)+\left(x+2\right)=\left(x+2\right)\left(x^2+1\right)\)
10: \(=x^2\left(x+2\right)-\left(x+2\right)=\left(x+2\right)\left(x-1\right)\left(x+1\right)\)
11: \(=x^3+5x^2-6x^2-30x+9x+45\)
\(=\left(x+5\right)\left(x^2-6x+9\right)\)
\(=\left(x+5\right)\left(x-3\right)^2\)