因式分解：18a^2b^3+12a^2b^2-9a^3b

18a^2b^3+12a^2b^2-9a^3b
=3a²b(6b²+4b-3a)
2、（2x-y+z）^2-(x-2y+z)^2
=(2x-y+z+x-2y+z)(2x-y+z-x+2y-z)
=(3x-3y+2z)(x+y)
3、4(x+2)^2-12(x+2)(x+3)+9(x+3)^2
=[2(x+2)-3(x+3)]²
=(-x-5)²
=(x+5)²
4、(x^2-2x)^2-2(x^2-2x)-15
=(x²-2x-5)(x²-2x+3)