1) 17/20 + 0,7 = 17/20 + 7/10 = 17/20 + 14/20 = 31/20 = 1,55
17/20 - 0,7 = 17/20 - 7/10 = 17/20 - 14/20 = 3/20 = 0,15
2) 13/25 + 0,37 = 13/25 + 37/100 = 325/100 + 37/100 = 362/100 = 3,62
13/25 - 0,37 = 13/25 - 37/100 = 325/100 - 37/100 = 288/100 = 2,88
3) 0,13 + 4/5 = 13/100 + 4/5 = 13/100 + 80/100 = 93/100 = 0,93
0,13 - 4/5 = 13/100 - 4/5 = 13/100 - 80/100 = - 67/100 = - 0,67
4) 5/9 + 0,4 = 5/9 + 4/10 = 50/90 + 36/90 = 86/90 = 43/45
5/9 - 0,4 = 5/9 - 4/10 = 50/90 - 36/90 = 14/90 = 7/45
5) 2/13 + 0,07 = 2/13 + 7/100 = 200/1300 + 91/1300 = 291/1300
2/13 - 0,07 = 2/13 - 7/100 = 200/1300 - 91/1300 = 73/1300
6) 0,1 + 6/17 = 1/10 + 6/17 = 17/170 + 60/170 = 77/170
0,1 - 6/17 = 1/10 - 6/17 = 17/170 - 60/170 = - 43/170