初一 数学 幂的运算 请详细解答,谢谢! (17 20:40:23)

m2+m-1=0,求m3+2m2+2000的值。
2025-04-29 00:35:20
推荐回答(3个)
回答1:

m²=-m+1
m³=m*m²=m(-m+1)=-m²+m

所以m³+2m²+2000
=-m²+m+2m²+2000
=m²+m+2000
=(-m+1)+m+2000
=2001

回答2:

m^2+m-1=0
m^2+m=1

m^3+2m^2+2000
=(m^2+m)m+m^2+2000
=1*m+m^2+2000
=(m+m^2)+2000
=1+2000
=2001

不懂再问,诚答!

回答3:

m²=1-m
∴m³+2m²+2000=m³+m²+m²+2000
=m²(m+1)+m²+2000
=(1-m)(1+m)+m²+2000
=1-m²+m²+2000
=2001