а)5/12+7/8=10/24+21/24=31/24=1 24/7
б)17/9+2 2/3 = 17/9 +24/9=41/9 =4 5/9
а)5/6-9/14=35/42-27/42=8/42=4/21
б)4 7/15-2 11/20=4 28/60-2 33/60= 3 88/60-2 33/60 = 1 55/60 =1 11/12
а)5/12+7/8=10/24+21/24=31/24=1 24/7
б)17/9+2 2/3 = 17/9 +24/9=41/9 =4 5/9
а)5/6-9/14=35/42-27/42=8/42=4/21
б)4 7/15-2 11/20=4 28/60-2 33/60= 3 88/60-2 33/60 = 1 55/60 =1 11/12