1: \(=3x^2+9x-2x-6=\left(x+3\right)\left(3x-2\right)\)
2: \(=3\left(x^2+x-2\right)=3\left(x+2\right)\left(x-1\right)\)
3: \(=3\left(x^2-x-2\right)=3\left(x-2\right)\left(x+1\right)\)
4: \(=6x^2-9x-4x+6=\left(2x-3\right)\left(3x-2\right)\)
5: \(=6x^2+9x+4x+6=\left(2x+3\right)\left(3x+2\right)\)
6: \(=3\left(2x^2+5x+2\right)=3\left(2x+1\right)\left(x+2\right)\)