几道数学题急啊对了再加20分
(x+y)^2-(x+y)^3
(x-y)^2-(x-y)^3
(x-y)^2-(y-x)^3
2(x-y)-3(y-x)^2
4ab(a+b)^2-6a^2b(a+b)
(x+y)(x-y)-(x+y)^2
8a(x-y)^2-4b(y-x)
a=-5a+b+c=-5.2求代数式a^2(-b-c)-3.2a(c+b)的值