1: \(=\left(x+5\right)\left(x-4\right)\)
2: \(=\left(x-5\right)\left(x+4\right)\)
3: \(=2x^2-4x+x-2=\left(x-2\right)\left(2x+1\right)\)
4: \(=3x^2+3x-2x-2\)
\(=\left(x+1\right)\left(3x-2\right)\)
5: \(4x^2-7x-2\)
\(=4x^2-8x+x-2=\left(x-2\right)\left(4x+1\right)\)
6: \(=4x^2+8x-3x-6=\left(x+2\right)\left(4x-3\right)\)