6 1/6+5 5/12-3 4/5-(6 1/7-3 9/28

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)