Odpowiedź:
zad 5
a)
2 3/20 + 3/4 = 2 3/20 + 15/20 = 2 17/20
1 3/18 + 2 4/9 + 5/6 = 1 3/18 + 2 8/18 + 15/18 = 3 26/18 = 4 8/18 = 4 4/9
3 1/2 + 2 3/4 + 1 1/3 = 3 6/12 + 2 9/12 + 1 4/12 = 6 19/12 = 7 7/12
b)
2 1/20 - 3/4 = 2 1/20 - 15/20 = 1 21/20 - 15/20 = 1 6/20 = 1 3/10
1 7/18 - 2 2/9 = 1 7/18 - 2 4/9 = 1 7/18 - 1 13/18 = - 6/18 = - 1/3
2 1/7 - 5 2/3 = 2 3/21 - 5 14/21 = - 3 11/21
