=4.73-2又3分之2-2.63-3分之1=(4.73-2.63)-(2又3分之2+3分之1)=2.1-3=-0.9
=4.73-(8/3+2.63)-1/3=4.73-8/3-1/3-2.63=4.73-2.63-3=-0.9
