Ответ:

  1. НОК(6, 8) = 24: 1/6 + 5/8 = 4/24 + 15/24 = 19/24.

  2. 15/20 = 3/4; НОК(4, 18) = 36: 3/4 + 11/18 = 27/36 + 22/36 = 49/36 = 1 13/36.

  3. НОК(21, 14) = 42: 11/21 − 31/14 = 22/42 − 93/42 = −71/42 = −1 29/42.

  4. 0,35 = 35/100 = 7/20; НОК(6, 20) = 60: 5/6 − 7/20 = 50/60 − 21/60 = 29/60.