Question

ДАЮ 80 БАЛЛОВ!!! ВОПРОС НА ФОТО ​

Answer 1

$1)\\\dfrac{t^{2} }{t^{2}-u^{2} } =\dfrac{5t^{2} }{5(t^{2} -u^{2}) } \\\\\\\dfrac{t-u}{5t+5u} =\dfrac{(t-u)\cdot(t-u)}{5\cdot(t+u)\cdot(t-u)} =\dfrac{t^{2} -2tu+u^{2} }{5(t^{2}-u^{2} ) } \\\\\\2)\\\dfrac{t^{2} }{t^{2}-u^{2} } =\dfrac{5t^{2} }{5(t +u) (t-u)} \\\\\\\dfrac{t-u}{5t+5u} =\dfrac{(t-u)\cdot(t-u)}{5\cdot(t+u)\cdot(t-u)} =\dfrac{t^{2} -2tu+u^{2} }{5(t+u ) (t-u)}$