(1,8+2,9-1,4)* 5 целых 1,7 : (7,9-2,3+1,6

(1/8+2/9-1/4)*5 1/7:(7/9-2/3+1/6)=1 4/5
1) 1/8+2/9=9/72+16/72=25/72
2)  25/72-1/4=25/72-18/72=7/72
3) 7/9-2/3=7/9-6/9=1/9
4) 1/9+1/6=6/54+9/54=15/54
5) 7/72*5 1/7=7/72*36/7=1/2
6) 1/2:15/54=1/2*54/15=27/15=1 12/15=1 4/5