Вправи 1201 - 1300 » 1258

Обчисли: 1) 417/19 + 10/19 = 427/19 = 4 + 18/19 = 58/19 2) 810/13 + 78/13 = (8 + 7) + (10/13 + 8/13) = 15 + 18/13 = 15 + 15/13 = 165/13 3) 74/23 – 117/23 = 627/23 – 217/23 = (6 – 2) + (27/23 – 17/23) = 4 + 10/23 = 410/23 4) 1411/27 – 812/27 = 1338/27 – 812/27 = 526/27 5) 181/17 – 710/17 = 1718/17 – 710/17 = 108/17 6) 83/31 – 28/31 = 734/31 – 28/31 = 76/31