计算9-12(x-y)+4(x+y)^2 81(a-b)^2-4(a+v)^2 -2x^3+8x^2-8x

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计算9-12(x-y)+4(x+y)^2 81(a-b)^2-4(a+v)^2 -2x^3+8x^2-8x
计算9-12(x-y)+4(x+y)^2 81(a-b)^2-4(a+v)^2 -2x^3+8x^2-8x

计算9-12(x-y)+4(x+y)^2 81(a-b)^2-4(a+v)^2 -2x^3+8x^2-8x
(1) 4x^3+8x^2-15x-9
= 4x^3+2x^2+6x^2-15x-9
= 2x^2(2x+1)+3(2x^2-5x-3)
= 2x^2(2x+1)+3(x-3)(2x+1)
= (2x^2+3x-9)(2x+1)
= (2x-3)(x+3)(2x+1)