Question

СРОЧНО ПОМОГИТЕ ДАЮ 30 БАЛЛОВ
7/8*8/7*9/10*10/9*11/12*12/11*13/14*14/13*15/16*16/15*17/18*18/17*19/20*20/19*21/22
упросите выражение

Answer 1

$frac{7}{8}*frac{8}{7}*frac{9}{10}*frac{10}{9}*frac{11}{12}*frac{12}{11}*frac{13}{14}*frac{14}{13}*frac{15}{16}*frac{16}{15}*frac{17}{18}*frac{18}{17}*frac{19}{20}*frac{20}{19}*frac{21}{22}= \\ = frac{7*8}{8*7}*frac{9*10}{10*9}*frac{11*12}{12*11}*frac{13*14}{14*13}*frac{15*16}{16*15}*frac{17*18}{18*17}*frac{19*20}{20*19}*frac{21}{22} =\\ = 1*1*1*1*1*1*1*frac{21}{22} = \\ = frac{21}{22}$

Answer 2

Ответ смотри на фото.