降次法数学题
发布网友
发布时间:2022-05-02 21:49
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热心网友
时间:2022-06-27 14:21
3x*x-x-1=0,3x*x=x+1,3x*x-x=1
6x*x*x+7x*x-5x+2002
=2x(3x*x)+7x*x-5x+2002
=2x(x+1)+7x*x-5x+2002
=9x*x-3x+2002
=3(3x*x-x)+2002
=3+2002
=2005
热心网友
时间:2022-06-27 14:22
x*x=(x+1)/3
6*x*x*x+7*x*x-5*x+2002
=6x*(x+1)/3+7*(x+1)/3-5*x+2002
=2x*x+2x-5x+7x/3+2002
=2*(x+1)/3-8x/3+2002+7/3
=2x/3+2/3-8x/3+2002+7/3
=2005