先化简再求值:3x^3-[x^3+(6x^2-7x)]-2(x^3-3x^2-4x),其中x=-1

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先化简再求值:3x^3-[x^3+(6x^2-7x)]-2(x^3-3x^2-4x),其中x=-1先化简再求值:3x^3-[x^3+(6x^2-7x)]-2(x^3-3x^2-4x),其中x=-1先化

先化简再求值:3x^3-[x^3+(6x^2-7x)]-2(x^3-3x^2-4x),其中x=-1
先化简再求值:3x^3-[x^3+(6x^2-7x)]-2(x^3-3x^2-4x),其中x=-1

先化简再求值:3x^3-[x^3+(6x^2-7x)]-2(x^3-3x^2-4x),其中x=-1
3x^3-[x^3+(6x^2-7x)]-2(x^3-3x^2-4x)
=3x^3-[x^3+6x^2-7x]-(2x^3-6x^2-8x)
=3x^3-x^3-6x^2+7x-2x^3+6x^2+8x
=15x
=15*(-1)
=-15