设m²+m-1=0,则m³+2m²+1997=

问题描述:

设m²+m-1=0,则m³+2m²+1997=

m²+m-1=0
m³+m²=m
m³+2m²+1997
m³+m²+m²+1997
=m²+m+1997
=1998