Решите пример 2 целых 5/9 — 1 целая 20/21): 1 целую 8/49+1 целая 8/9:6=_______

(9*2+5/9-21*1+20/21): 49*1+8/49+9*1+8/9:6=(23/9-41/21): 57/49+17/9:6=(7*23/63-3*41/63): 57/49+17/9:6=(161/63-123/63): 57/49+102/9=38/63:57/49+102/9=38*49/63*57+102/9=1862/3591+102/9=1862+399*102/3591=42560/3591=12 целых 468/3591