x^2-3x=1=0,求2(x^3)-3(x^2)-7x+2009
问题描述:
x^2-3x=1=0,求2(x^3)-3(x^2)-7x+2009
答
2(x^3)-3(x^2)-7x+2009
=2x*(x^2-3x+1)+3(x^2-3x+1)+2006
=2006