Question

(m-n)^7/(n-m)^6+(-m-n)^3/(m+n)^2

是不是=-2n啊？我算到算到脑袋有点昏了！

Answer 1

(m-n)^7/(n-m)^6+(-m-n)^3/(m+n)^2
=(m-n)^7/(m-n)^6 + -(m+n)^3/(m+n)^2
=m-n-(m+n)
=-2n