+x= x﹣15%x=170 x:=:2
1.85﹣+= 1÷×= +0.375=
2.4﹣= (+)×2.4= 5÷×5÷=
10×45%= 1.25×8= 40×(1﹣20%)=
①12.7﹣3.6﹣5.4
②15×43%+85×0.43
③0.25×80+45÷
①3.25×3.6+7.75×3.6﹣3.6
②9.9×25
③
④