Odpowiedź :
a) 20/21 - 1/3 = 20/21 - 7/21 = 13/21
b) 5/12 + 2 i 3/8 = 10/24 + 2 i 9/24 = 2 i 19/24
20/21- 3/22= 17/21
5/12 +19/8= 10/24 + 57/24 = 67/24= 2 i 16/24 = 2 i 2/3
5/12 +19/8= 10/24 + 57/24 = 67/24= 2 i 16/24 = 2 i 2/3