А) 3/14 - 9/17 - 8/17 + 1/14 = 4/14 - 15/17 = 142/238 = 71/119 б) 9/19 - 4/5 - 3/5 + 10/19 = 19/19 -7/5 = 1 - 1 2/5 = -2/5 в) 44/57 + 8/13 - 20/57 - 8/13 = 24/57 г) -28/71 + 5/7 + 4/7 - 43/71 = - 71/71 + 9/7 = -1 + 1 2/7 = 2/7