Найдите значение выражения (2 5/9-1 20/21):1 8/49+1 8/9:6

(2 5/9-1 20/21):1 8/49+1 8/9:6=5/62 5/9-1 20/21=2 35/63-1 60/63=1-25/63=63/63-25/63=38/6338/63:1 8/49=38/63:57/49=38/63*49/57=14/271 8/9:6=17/9*1/6=17/5414/27+17/54=28/54+17/54=45/54=5/6