1.(4,16-2 3\4 -3,85)= 2.(9 4/5-3,-8 1/20)= 3.(6,8-4 13/ 17/50-2,64)= 4.(7,85-1 3/ 9/25-2,16)= sos !

1.(4,16-2 3\50)-(5 3\4 -3,85)=(4,16-2,06)-(5,75-3,85)=2,1-1,9=0,2
2.(9 4/5-3,75)-(10-8 1/20)=(9,8-3,75)-(10-8,05)=6,05-1,95=4,1
3.(6,8-4 13/20)-(3 17/50-2,64)=(6,8-4,65)-(3,34-2,64)=2,15-0,7=1,45
4.(7,85-1 3/20)-(5 9/25-2,16)=(7,85-1,15)-(5,36-2,16)=6,7-3,2=3,5