11 + 37 7/9 - 47 31/36 + 51 17/42 - 12 9/28 - 26 2/3+ 1/6 решите кто может важно

11 + 37 7/9 - 47 31/36 + 51 17/42 - 12 9/28 - 26 2/3+ 1/6 =13 1/2

1)11+37 7/9=48 7/9
2)48 7/9-47 31/36=1 28/36-31/36=64/36-31/36=33/36=11/12
3)11/12+51 17/42=77/84+51 34/84=51 111/84=52 27/84=52 9/28
4)52 9/28-12 9/28=40
5)40-26 2/3=39 3/3-26 2/3=13 1/3
6)13 1/3+1/6=13 2/6+1/6=13 3/6=13 1/2 или 13,5