M/m+n и n/m-n

To simplify the expressions:

For m/(m+n):

1. There is no common factor to simplify the numerator and denominator.
2. Therefore, the expression cannot be simplified further.

For n/(m-n):

1. There is no common factor to simplify the numerator and the denominator.
2. Therefore, the expression cannot be simplified further.

Please note that these expressions cannot be simplified unless additional information or values are provided for the variables m and n.