①ab^2- ab(b-a)+(-2a)^2 ·x
=ab^2-ab^2-a^2b+4a^2X
=-a^2b+4a^2X
②1/3 x(-x^2 +2x-1 )-1/3x^2(2x-6x^2)
=-1/3x^3+2/3x^2-1/3x-2/3x^3+2x^4
=2x^4-x^3+2/3x^2-1/3x