已知,m²+m-1=0,则m³+2m²-2007的值是

来源:学生作业帮助网 编辑:作业帮 时间:2024/10/01 03:11:29
已知,m²+m-1=0,则m³+2m²-2007的值是
x){}KurՔ -su m tv XZkAet ̟jyڰٌ6IEj/S6\4YK}pCl |t32&ky% .D"AL3<;l8c jms5L75! (1H<_o]`y[g Ov/}vʳP[G[QB+ulA$\ak\ &6i,bvȎgsfhH=|

已知,m²+m-1=0,则m³+2m²-2007的值是
已知,m²+m-1=0,则m³+2m²-2007的值是

已知,m²+m-1=0,则m³+2m²-2007的值是
由题意得
m²+m=1
m³+2m²-2007
=m【m²+m+m】-2007
=m【m+1】-2007
=m²+m-2007
=1-2007
=-2006

m^3+2m^2-2007=m(m^2+m-1)+m^2+m-2007=m^2+m-2007.又由已知可推出m^2+m=1所以答案是-2006.

∵m²+m-1=0,
∴m²+m=1
则m³+2m²-2007
=m³+m²+m²-2007
=m(m²+m)+m²-2007
=m+m²-2007
=1-2007
=-2006
希望能采纳