Question

помогите, пожалуйста

Answer 1

$frac{5k(k+3)-14k}{ (k+3)^{2} } * frac{(k+3)(k-3)}{5k+1}+ frac{3(k-3)}{k+3}= frac{5 k^{2} +15k-14k}{k+3}* frac{k-3}{5k+1}+ frac{3(k-3)}{k+3}= \ \ = frac{k(5k+1)}{k+3}* frac{k-3}{5k+1} + frac{3(k-3)}{k+3}= frac{k(k-3)}{k+3}+ frac{3(k-3)}{k+3}= frac{(k-3)(k+3)}{(k+3)}=k-3$