先化简再求值(3x+2)(3x-2)-5x(x-1)-(2x-1)^2其中x=-1/3

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先化简再求值(3x+2)(3x-2)-5x(x-1)-(2x-1)^2其中x=-1/3先化简再求值(3x+2)(3x-2)-5x(x-1)-(2x-1)^2其中x=-1/3先化简再求值(3x+2)(3

先化简再求值(3x+2)(3x-2)-5x(x-1)-(2x-1)^2其中x=-1/3
先化简再求值(3x+2)(3x-2)-5x(x-1)-(2x-1)^2其中x=-1/3

先化简再求值(3x+2)(3x-2)-5x(x-1)-(2x-1)^2其中x=-1/3
(3x+2)(3x-2)-5x(x-1)-(2x-1)^2
=9x^2-4-5x^2+5x-4x^2+4x-1
=9x-5
=9*(-1/3)-5
=-8.

(3x+2)(3x-2)-5x(x-1)-(2x-1)^2
=9x^2-4-5x^2+5-4x^2+4x-1
=4x
=-4/3

(3x+2)(3x-2)-5x(x-1)-(2x-1)^2
=9x^2-4-5x^2+5x-4x^2+4x-1
=9x-5
=9*(-1/3)-5
=-8.

=9x^2-4-5x^2+5x-4x^2-1+4x
=9x-5 当x=-1/3时
=9*(-1/3)-5
=-3-5
=-8

(3x+2)(3x-2)-5x(x-1)-(2x-1)^2
=(3x)^2-2^2-(5x^2-5x)-[(2x)^2-2*(2x)+1]
=9x^2-4-5x^2+5x-4x^2+4x-1
=9x-5
=9*(-1/3)-5
=-3-5
=-8