已知x的2次方+x-1=0 求3x²+3x+2的值
问题描述:
已知x的2次方+x-1=0 求3x²+3x+2的值
已知m²+m-1=0,求m³+2m²+2010的值
答
x^2+x-1=0
x^2+x=1
3x²+3x+2
=3(x^2+x)+2
=3+2
=5
m²+m-1=0
m^3+m^2-m=0
m^3+2m^2=m^2+m
m²+m-1=0
m^2+m=1
m³+2m²+2010
=m^2+m+2010
=1+2010
=2011