1) 22,2:5 2/7-2 3/5=1,6
22,2=22 2/10= 222/10= 111/5
111/5:5 2/7=111/5: 37/7= 111/5*7/37=777/185
777/185-2 3/5= 777/185-13/5=(777-481)/185=296/185=1,6
2) (7 1/4-6 7/18)*7,2+2,8=9
7 1/4-6 7/18= 29/4-115/18= (261-230)/36= 31/36
31/36*7,2= 31/36*7 2/10= 31/36*72/10=62/10=6,2
6,2+2,8=9