x^2-3x=1=0,求2(x^3)-3(x^2)-7x+2009

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x^2-3x=1=0,求2(x^3)-3(x^2)-7x+2009

x^2-3x=1=0,求2(x^3)-3(x^2)-7x+2009
x^2-3x=1=0,求2(x^3)-3(x^2)-7x+2009

x^2-3x=1=0,求2(x^3)-3(x^2)-7x+2009
2(x^3)-3(x^2)-7x+2009
=2x*(x^2-3x+1)+3(x^2-3x+1)+2006
=2006

x^2-3x+1=0
x^2+1=3x
x^2-3x+1=0
x^2=3x-1
x^2-3x+1=0
显然x不等于0
所以两边除以x
x-3+1/x=0
x+1/x=3
2x^2-5x-2+3/x^2+1
=2(3x-1)-5x-2+3/3x
=6x-2-5x-2+1/x
=x-4+1/x
=3-4
=-1

2x^3-3x^2-7x+2009=2x(x^2-3x+1)+3(x^2-3x+1)+2006=2006