1) 2 5/18 - 1,25 = 2 5/18 - 1 1/4 = 2 10/36 - 1 9/36 = 1 1/36
2) 1 1/36 : 4 1/9 = 37/36 * 9/37 = 1/4
3) 7/15 - 5/12 = 28/60 - 25/60 = 3/60 = 1/20
4) 1/20 * 5 = 1/4
5) 1/4 : 1/4 =1
6) 3 5/9 - 2,2 = 3 5/9 - 2 1/5 = 3 25/45 - 2 9/45 = 1 16/45
7) 1 16/45 - 2/15 = 1 16/45 - 6/45 = 1 10/45 = 1 2/9
9) 1 2/9 * (-3/11) = 11/9 * (-3/11)= -1/3
10) 1 7/9 - 2 = -2/9
11) -2/9 * 2,25 = -2/9 * 9/4 = - 1/2
12) -1/3 : (-1/2) = 1/3 * 2/1 = 2/3
13) 1 + 2/3 = 1 2/3
ответ : 1 2/3