Question

найдите выражения 19разделить на 20/21-21/22

Answer 1

$\displaystyle \dfrac{19}{\frac{20}{21} ^{(22} -\frac{21}{22} ^{(21} } = \dfrac{19}{\frac{20\cdot 22-21\cdot 21}{21\cdot 22}} =\\\\\\=19\cdot \dfrac{(20+1)\cdot 22}{20\cdot 22-(20+1)\cdot 21} =\\\\\\=19\cdot \dfrac{20\cdot 22+22}{20\cdot 22-(20\cdot 21+21)} =\\\\\\=19\cdot \dfrac{440+22}{20\cdot (22-21)-21} =\\\\\\=19\cdot \dfrac{462}{20-21} =\\\\\\=(20-1)\cdot (-462)=-(9240-462)=\\\\=-(9000-222)=\bold{-8778}$