已知x2+x-1=0,则x3+2x2+2011=_.
问题描述:
已知x2+x-1=0,则x3+2x2+2011=______.
答
∵x2+x-1=0,
∴x3+2x2+2011
=x(x2+x-1)+x2+x+2011
=x2+x-1+2012
=0+2012
=2012.
故答案为:2012.