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)^32(x-y)-3(y-x)^24ab(a+b)^2-6a^2b(a+b)(x+y)(x-y)-(x+y)^28a(x-y)^2-4b(y-x)a=-5 a+b+c=-5.2求代数式a^2(-b-c)-3.2a(c+b)的值
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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)^32(x-y)-3(y-x)^24ab(a+b)^2-6a^2b(a+b)(x+y)(x-y)-(x+y)^28a(x-y)^2-4b(y-x)a=-5 a+b+c=-5.2求代数式a^2(-b-c)-3.2a(c+b)的值
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=-5 a+b+c=-5.2求代数式a^2(-b-c)-3.2a(c+b)的值
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)^32(x-y)-3(y-x)^24ab(a+b)^2-6a^2b(a+b)(x+y)(x-y)-(x+y)^28a(x-y)^2-4b(y-x)a=-5 a+b+c=-5.2求代数式a^2(-b-c)-3.2a(c+b)的值
1.=(x+y)^2(1-x-y)
2.=(x-y)^2(1-x+y)
3.=(x-y)^2(1+x-y)
4.=(x-y)(2-3x+3y)
5.=2ab(a+b)(2a+2b-3a)=2ab(a+b)(-a+2b)
6.=(x+y)(x-y-x-y)=-2y(x+y)
7.=(x-y)(8ax-8ay+4b)
8.=-a(b+c)(a+3.2)=-(-5)(-0.2)(-5+3.2)=1.8
(x+y)^2-(x+y)^3=(x+y)^2*(1-x-y)
(x-y)^2-(x-y)^3=(x-y)^2*(1-x+y)
(x-y)^2-(y-x)^3=(x-y)^2*(1+x-y)
2(x-y)-3(y-x)^2=(x-y)(2-3x+3y)
4ab(a+b)^2-6a^2b(a+b)=2ab(a+b)(2b-a)
(x...
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(x+y)^2-(x+y)^3=(x+y)^2*(1-x-y)
(x-y)^2-(x-y)^3=(x-y)^2*(1-x+y)
(x-y)^2-(y-x)^3=(x-y)^2*(1+x-y)
2(x-y)-3(y-x)^2=(x-y)(2-3x+3y)
4ab(a+b)^2-6a^2b(a+b)=2ab(a+b)(2b-a)
(x+y)(x-y)-(x+y)^2=-2y(x+y)
8a(x-y)^2-4b(y-x)=4(x-y)(2ax-2ay+b)
a=-5 a+b+c=-5.2 b+c=-0.2
a^2(-b-c)-3.2a(c+b)=-25(b+c)+16(b+c)=9*0.2=1.8
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