[1-(+)]÷ 2÷× (8.9-7.7)÷0.2×0.15
4:1.25=x:0.75
185+35=
6.4-3.8=
①7.34 ×70%+ ×7.34
②9.6+10.4×25%
③250×(1+20% )×(1-10% )
0.25×1.25÷ 8.5×80%+1.5÷
( + )×17×21 2022 ×
9.6÷0.08× (4-2.75)
1.25×32×2.5
1÷-
15÷