14-13,2:(3 11\21-2 4\15)+(7 1\4-6 7\18)*7,2+2,8 = 12,5
3 11\21-2 4\15 = 3 55/105 - 2 28/105 = 1 27/105 = 1 9/35
13,2:1 9/35 = 13 2/10 : 44/35 = 13 1/5 * 35/44 = 66/5*35/44=21/2 = 10 1/2= 10,5
7 1\4-6 7\18 = 7 9/36 - 6 14/36 = 6 45/36 - 6 14/36 = 31/36
31/36*7,2 = 31/5 = 6 1/5 = 6,2
14 - 10,5 + 6,2 + 2,8 = 12,5