Question

3m^2 - 3mn/m^3- n^3 помогите

Answer 1

$frac{3m^{2}-3mn }{m^{3}-n^{3} } = frac{3m(m-n)}{(m-n)( m^{2}+mn+n^{2}) } = frac{3m}{m^{2}+mn+n^{2} }$