Question

20mn-4m^2дробная чертаm^2-10mn+25n^2 помогите плиз

Answer 1

$\frac{20mn-4 m^{2} }{ m^{2} -10mn+25 n^{2} } = \frac{4m(5n-m)}{ (m-5n)^{2} } =- \frac{4m(m-5n)}{(m-5n)(m-5n)} =- \frac{4m}{m-5n} = \frac{4m}{5n-m}$