来自冯益明的问题
若m²+m-1=0,求m³+2×m²+2009等于什么
若m²+m-1=0,求m³+2×m²+2009等于什么
1回答
2020-07-17 12:52
若m²+m-1=0,求m³+2×m²+2009等于什么
若m²+m-1=0,求m³+2×m²+2009等于什么
因为m²+m-1=0--------
所以,m²=1-m,m=1-m²---
m³+2×m²+2009=m²*m+2×m²+2009
=m²*(m+2)+2009
=(1-m)*(m+2)+2009
=m+2-m²-2m+2009
=[(1-m²)-m]+2010-----------上面有这个m=1-m²---
=2010
----------------------------------------------------------------OK啦---------------------------------