§ 4. Звичайні дроби » 847

847. Обчисліть: 1) 64/9 + 35/9 = 99/9 = 9 + 1 = 10 2) 1011/19 + 514/19 = 1525/19 = 15 + 16/19 = 166/19 3) 15/8 + 37/8 = 412/8 = 54/8 4) 1 – 3/11 = 11/11 – 3/11 = 8/11 5) 1 – 13/40 = 40/40 – 13/40 = 27/40 6) 4 – 14/7 = 37/7 – 14/7 = 23/7 7) 10 – 93/10 = 910/10 – 93/10 = 7/10 8) 52/7 – 25/7 = 49/7 – 25/7 = 24/7 9) 146/20 – 812/20 = 1326/20 – 812/20 = 514/20 10) 83/14 – 59/14 = 717/14 – 59/14 = 28/14 11) 710/21 – 413/21 = 631/21 – 416/21 = 215/21 12) 148/31 – 68/31 = 8