(m-n)^7/(n-m)^6+(-n-m)^3/(m+n)^2
问题描述:
(m-n)^7/(n-m)^6+(-n-m)^3/(m+n)^2
急用!
答
(m-n)^7/(n-m)^6+(-n-m)^3/(m+n)^2
=(m-n)^7/(m-n)^6-(m+n)^3/(m+n)^2
=(m-n)-(m+n)
=m-n-m-n
=-2n