5.94 ÷【2.4 ×(5-0.5)】=5.94÷(2.4×4.5)=5.94÷2.4÷4.5=0.66÷1.2=0.55.
5.94÷[2.4×(5-0.5)]=5.94÷(2.4×5-2.4×0.5) =5.94÷(1.2-0.12) =5.94÷1.08=5.5