脱式计算6又1/6-0.72x5/9+3又1/2÷1.4=6又1/6-0.4+2.5=6又1/6+(2.5-0.4)=6又1/6+2.1=8又4/15
6又1/6一0.72X5/9十3又1/2÷1.4二37/6一18/25X5/9+7/2X10/14二37/6一5/2十5/2二6又1/6
