1: \(6x^3-9x^2=3x^2\left(2x-3\right)\)
2: \(x^3-x^4=x^3\left(1-x\right)\)
3: \(=2xy\left(2x-4y+9xy\right)\)
4: \(-8x^4y^3-12x^2y^4+20x^3y^4\)
\(=-4x^2y^3\left(2x^2y+3y-5xy\right)\)
`5)18x^2y-12x^3=6x^2(3y-2x)`
`6)3xy^2+6xy^2=9xy^2`
`7)x^m+2-x^m=2`
`8)5x^m+2+10x^2=6x^m+2(1+5x^2)`