6 1/6+5 5/12-3 4/5-(6 1/7-3 9/28=
(6•6+1)/6+ (5•5+12)/5- (5•3+4)/5 - ( (6•7+1)/7 - (28•3+9)/28 )=
37/6+ 37/12- 19/5 - (43/7 -93/28)=
(37•2)/(6•2)+ 37/12- 19/5- (43•4)/(7•4)+ 93/28=
74/12+ 37/12- 19/5- 172/28+ 93/28=
111/12- 19/5 - 79/28=
(111•5)/(12•5)- (19•12)/(5•12) - 79/28=
555/60 - 228/60 - 79/28=
327/60- 79/28=
5 27/60 - 2 23/28=
5-2+ 27/60- 23/28=
3+ 9/20 - 23/28=
3 (9•7)/(20•7) - (23•5)/(28•5) =
3 63/140- 115/140=
2 (140•1+63)/140 -115/140=
2 203/140 - 115/140=
2 88/140= 2 22/35;
(27/60 поделили на 3, уменьшили дробь =9/20)