10减去4又2分之1除以3的商,
10-[(4+1/2)+(1+9/10)] =10-(9/2+19/10) =10-(45/10+19/10) =10-64/10 =-54/10 (-54/10) / (2+4/5) =(-54/10) / (14/5) =-27/14
10-[(4+1/2)+(1+9/10)] =10-(9/2+19/10) =10-(45/10+19/10) =10-64/10 =-54/10 (-54/10) / (2+4/5) =(-54/10) / (14/5) =-27/14收起