(1)-2x^2-12xy^2+8xy^3
=-2x(x+6y^2-4y^3)
(2)(m-n)^2-(n-m)（m+2n)
=(m-n)^2+(m-n)（m+2n)
=(m-n)[(m-n)+(m+2n)]
=(m-n)(2m+n)
（3）3.2*1.54+1.54*2.8-2*1.54
=1.54*(3.2+2.8-2)
=1.54*4
=6.16
（4）3^2007-5*3^2006+6*3^2005.
=3^2005*(3^2-5*3+6)
=3^2005*(9-15+6)
=3^2005*0
=0
（5）6x^3 y(x-y)^3 -4xy^3(y - x)^2
=6x^3 y(x-y)^3 -4xy^3(x-y)^2
=2xy(x-y)^2[3x^2(x-y)-2y^2]
=2xy(x-y)^2(3x^3-3x^2y-2y^2)