а)1,25-4 целых 1/12
б)-2целых 1/8-3,4
в)5*(-2/3)+1,8
1 1/4- 4 1/12= 1 4/12 - 4 1/12 = -3 3/12 - 2 1/8- 3 2/5 = -2 5/40 - 3 16/40 = -5 21/40 -10/3+ 1 4/5 =-50/15+1 12/15= -50/15+37/15=-13/15