已知m^2+m-1=0,n^2-n-1=0,求代数式m^3+n^3+2m^2-2n^2+2008的值.

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已知m^2+m-1=0,n^2-n-1=0,求代数式m^3+n^3+2m^2-2n^2+2008的值.
已知m^2+m-1=0,n^2-n-1=0,求代数式m^3+n^3+2m^2-2n^2+2008的值.

已知m^2+m-1=0,n^2-n-1=0,求代数式m^3+n^3+2m^2-2n^2+2008的值.
已知m^2+m-1=0(1) n^2-n-1=0(2) (1)-(2)得 m^2-n^2+m+n=0,而且m^2+m=1 ,n^2-n=1 所以m^3+n^3+2m^2-2n^2+2008=(m^3+m^2)+(n^3-n^2)+m^2-n^2+2008 =m(m^2+m)+n(n^2-n)+m^2-n^2+2008 =m+n+m^2-n^2+2008=2008