(kurde zazdroszczę ćwiczeń w 8 klasie)
a) 2 i 3/20 + 1/4 = 2 i 3/20 + 5/20 = 1 i 8/20
1 i 5/18 + 2 i 4/9 + 5/6 = 1 i 10/36 + 2 i 12/36 + 30/36 = 3 i 52/36 = 4 i 12/36
3 i 1/2 + 2 i 3/4 + 1 i 1/3 = 3 i 6/12 + 2 i 9/12 + 1 i 4/12 = 4 i 19/12 = 5 i 7/12
b) 2 i 1/20 - 3/4 = 2 i 1/20 - 15/20 = 1 i 6/20
1 i 7/18 - 2 i 2/9 = 1 i 7/18 - 2 i 4/18 = -1 i 3/18
2 i 1/7 - 5 i 2/3 = 2 i 3/21 - 5 i 14/21 = -4 i 10/21
Dwóch ostatnich nie jestem pewna :x
