7,2 * 2 1/12 : (15 1/5 - 11 1/2) = 4 2/37
1) 15 1/5 = 76/5
2) 11 1/2 = 23/2
3) 76/5 - 23/2 = 76*2/5*2 - 23*5/2*5 = 152/10 - 115/10 = (152-115)/10 = 37/10
4) 7,2 = 7 2/10 = 7 1/5 = 36/5
5) 2 1/12 = 25/12
6) 36/5 * 25/12 = 36*25/5*12 = 900/60 = 60*15/60 =15
7) 15 : 37/10 =15/1 * 10/37 = 15*10/1*37 = 150/37 = 4 2/37
Ответ: 4 2/37.