若m²+m+3=0,求m的5次方+3m的4次方+2m的3次方+2m2次方-10m的值.
问题描述:
若m²+m+3=0,求m的5次方+3m的4次方+2m的3次方+2m2次方-10m的值.
答
当m²+m+3=0时
m^5+3m^4+2m³+2m²-10m=m³(m²+m+3)+2m^4-m³+2m²-10m
=2m^4-m³+2m²-10m=2m²(m²+m+3)-3m³-4m²-10m=-3m³-4m²-10m
=-3m(m²+m+3)+3m²+9m-4m²-10m=-m²-m=-(m²+m+3)+3=3