(3x-y)²-2x(4x-5y)-(x+2y)²先化简再求值(3x-y)²-2x(4x-5y)-(x+2y)² 其中x=2000,y=-2

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(3x-y)²-2x(4x-5y)-(x+2y)²先化简再求值(3x-y)²-2x(4x-5y)-(x+2y)² 其中x=2000,y=-2
(3x-y)²-2x(4x-5y)-(x+2y)²
先化简再求值(3x-y)²-2x(4x-5y)-(x+2y)² 其中x=2000,y=-2

(3x-y)²-2x(4x-5y)-(x+2y)²先化简再求值(3x-y)²-2x(4x-5y)-(x+2y)² 其中x=2000,y=-2
(3x-y)²-2x(4x-5y)-(x+2y)²
=9x²-6xy+y²-8x²+10xy-x²-4xy-4y²
=-3y²
x=2000,y=-2
则原式=-3×(-2)²
=-3×4
=-12

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