已知m/n=5、,求（m/（m+n）)+(m/(m-n))-(n^2/(m^3-n^2))

题目

已知m/n=5、,求（m/（m+n）)+(m/(m-n))-(n^2/(m^3-n^2))

答案

已知m=5n,则原式=(5n/(5n+n))+(5n/(5n-n))-(n^2)/(((5n)^3)-n^2)=(5/6)+(5/4)-[1/(125n-1)]=(25/12)-[1/(125n-1)]