Odpowiedź:
a) 1/3 + 1/5 = 5/15 + 3/15 = 8/15
1/3 - 1/5 = 5/15 - 3/15 = 2/15
1/3 x 1/5 = 1/15
1/3 : 1/5 = 1/3 x 5/1 = 5/3 = 1 i 2/3
b) 1 i 1/4 + 2/3 = 1 i 3/12 + 8/12 = 1 i 11/12
1 i 1/4 - 2/3 = 1 i 3/12 - 8/12 = 15/12 - 8/12 = 7/12
1 i 1/4 x 2/3 = 5/4 x 2/3 = 10/12 = 5/6
1 i 1/4 : 2/3 = 5/4 x 3/2 = 15/8 = 1 i 7/8
c) 2 i 5/6 + 1 i 1/9 = 2 i 15/18 + 1 i 2/18 = 3 i 17/18
2 i 5/6 - 1 i 1/9 = 2 i 15/18 - 1 i 2/18 = 1 i 13/18
2 i 5/6 x 1 i 1/9 = 17/6 x 10/9 = 17/3 x 5/9 = 85/27= 3 i 4/27
2 i 5/6 : 1 i 1/9 = 17/6 x 9/10 = 17/2 x 3/10= 51/30= 1 i 21/30 = 1 i 7/10
