已知3x²-5x=2,求(2x-1)²-(x-1)(x+2)的值

已知3x²-5x=2,求(2x-1)²-(x-1)(x+2)的值
已知3x²-5x=2,求(2x-1)²-(x-1)(x+2)的值

已知3x²-5x=2,求(2x-1)²-(x-1)(x+2)的值
(2x-1)²-(x-1)(x+2)
=(4x²-4x+1)-(x²+x-2)
=4x²-4x+1-x²-x+2
=3x²-5x+3
=2+3
=5

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