m2+m-1=0,n2-n-1=0代数式m3+n3+2m2-2n2+2008的值
问题描述:
m2+m-1=0,n2-n-1=0代数式m3+n3+2m2-2n2+2008的值
答
m2+m-1=0,n2-n-1=0代数式m3+n3+2m2-2n2+2008的值m2+m-1=0,n2-n-1=0m^2+m=1,n^2-n=1m3+n3+2m2-2n2+2008=m^3+m^2+m^3-m^2+m^2-m^2+2008=m(m^2+m)+n(n^2-n)+m^2-n^2+2008=m+n+m^2-n^2+2008=(m^2+m)-(n^2-n)+2008=1-1+20...