①(-2ab)^2*(-a)^2+(2ab)^2*(-a)3*b
=(2ab)^2*a^2-(2ab)^2*a^3*b
=(2ab)^2*a^2*(1-ab)
②(-4a^2b)^3*(ac^2)2-(2a^4c^2)*(-a^2b^2)*c
=-64a^6b^3*a^2c^4+2a^4c^2*a^2b^2*c
=2a^6b^2c^3-64a^8b^3c^4
=2a^6b^2c^3(1-32a^2bc)
③(-a^5)/(-a)^2+(-3a^2)(-2a)
=-a^5/a^2+3a^2*2a
=-a^3+6a^3
=5a^3
④6x^2-(x-1)(x+2)-2(x-1)(x+3)
=6x^2-(x^2+x-2)-2(x^2+2x-3)
=6x^2-x^2-x+2-2x^2-4x+6
=3x^2-5x+8
⑤15x^8y^2z^4/(-3x^4yz^3)/(-4x^2y)
=15/3/4*x^8/x^4/x^2*y^2/y/y*z^4/z^3
=5/4*x^2z
⑥(0.16mn^4-0.6m^2n^3+1.4mn^3)/(-2/5mn^3）
=0.2mn^3(8n-3m+7)*5/(2mn^3）
=(8n-3m+7)/2