7. \(\frac{3m-4}{11mn^2}-\frac{4n+3}{22m^2n}\)

Общий знаменатель — \(22m^2n^2\):

\[\frac{3m-4}{11mn^2}-\frac{4n+3}{22m^2n}=\frac{2m(3m-4)-n(4n+3)}{22m^2n^2}=\frac{6m^2-8m-4n^2-3n}{22m^2n^2}.\]

Ответ: \(\frac{6m^2-8m-4n^2-3n}{22m^2n^2}\).