一道数学题。。急啊。。在线等

m^2=n+2
n^2=m+2
m^2-n^2=n-m
[m-n][m+n]=-[m-n]
m+n=-1

m^3-2mn+n^3
=m[n+2]-2mn+n[m+2]
=mn+2m-2mn+mn+2n
=2m+2n
=2[m+n]
=-2

m的平方＝n＋2，n的平方＝m＋2似乎只有在m=n=2的时候吧

m^2=n+2
n^2=m+2
(m+n)(m-n)=n-m
m+n=-1
m^3-2mn+n^3
=m(n+2)+n(m+2)-2mn
=2mn+2m+2n-2mn
=2(m+n)
=-2