1)
1/4 + 3/5 = 5/20 + 12/20 = 17/20 = 0,85
2/3 + 1/2 = 4/6 + 3/6 = 7/6 = 1 1/6
1/16 + 1/4 = 1/16 + 4/16 = 5/16 = 0,3125
2)
7/8 - 1/2 = 7/8 - 4/8 = 3/8 = 0,375
11/14 - 3/7 = 11/14 - 6/14 = 5/14
8/9 - 1/3 = 8/9 - 3/9 = 5/9
3)
11/18 - 2/9 = 11/18 - 4/18 = 7/18
9/16 - 1/4 = 9/16 - 4/16 = 5/16 = 0,3125
3/4 - 1/2 = 3/4 - 2/4 = 1/4 = 0,25
