(85/54 - х) + 8/9 = 25/27
85/54 - х = 25/27 - 8/9
85/54 - х = 25/27 - 24/27
85/54 - х = 1/27
х = 85/54 - 1/27
х = 85/54 - 2/54
х = 83/54
Проверка: (85/54 - 83/54) + 48/54 = 50/54 = 25/27
(85/54 - х) + 8/9 = 25/27
85/54 - х = 25/27 - 8/9
85/54 - х = 25/27 - 24/27
85/54 - х = 1/27
х = 85/54 - 1/27
х = 85/54 - 2/54
х = 83/54
Проверка: (85/54 - 83/54) + 48/54 = 50/54 = 25/27