Question

3mn-m/4m+n * 16m^2-n^2/3n-1

Answer 1

$frac{3mn-m}{4m+n} * frac{16 m^{2}- n^{2} }{3n-1}= frac{m(3n-1)}{4m+n} * frac{(4m+n)(4m-n)}{3n-1} =m(4m-n)=$$4 m^{2}-mn$