Question

Помогите срочно пожалуйста

Answer 1

$1) \ \dfrac{tg-g^{2} }{t^{2}-g^{2} } =\dfrac{g(t-g)}{(t-g)(t+g)} =\boxed{\dfrac{g}{t+g} }\\\\\\2) \ \dfrac{t+g}{2(t-g)} -\dfrac{t-g}{2(t+g)} -\dfrac{g}{t-g} =\dfrac{(t+g)\cdot(t+g)-(t-g)\cdot(t-g)-g\cdot2(t+g)}{2(t-g)(t+g)} =\\\\\\=\dfrac{t^{2} +2tg+g^{2}-t^{2} +2tg-g^{2} -2tg-2g^{2} }{2(t-g)(t+g)}=\dfrac{-2g^{2} +2tg}{2(t-g)(t+g)} =\\\\\\=\dfrac{2g(t-g)}{2(t-g)(t+g)} =\boxed{\dfrac{g}{t+g} }$