3 2/8 + 3 1/7 = 3 14/56 + 3 8/56 = 6 22/56 = 6 11/28
-4,7 - 4 2/7 = -4 49/70 - 4 20/70 = -8 69/70
-4,7 + 6 1/3 = -4 21/30 + 6 10/30 = 5 40/30 - 4 21/30 = 1 19/30
3 2/8 + 3 1/7 = 3 14/56 + 3 8/56 = 6 22/56 = 6 11/28
-4,7 - 4 2/7 = -4 49/70 - 4 20/70 = -8 69/70
-4,7 + 6 1/3 = -4 21/30 + 6 10/30 = 5 40/30 - 4 21/30 = 1 19/30