Question

计算;m/(m-n)-n/(m+n)+(2mn)/(m^2n^2)

Answer 1

解：原式=（m²+mn-mn+n²+2mn)/(m+n)(m-n)
=(m+n)²/(m+n)(m-n)
=(m+n)/(m-n)

Answer 2

m/(m-n)-n/(m+n)+2mn/(m^2-n^2)
=m(m+n)/[(m+n)(m-n)]-n(m-n)/[(m+n)(m-n)]+2mn/[(m+n)(m-n)]

=[m(m+n)-n(m-n)+2mn]/[(m+n)(m-n)]
=(m+n)^2/[(m+n)(m-n)]
=(m+n)/(m-n)