8100÷4÷75 75×27+19×25 31×870+13×310 4×(25×65+25×28)

问题描述:

8100÷4÷75
75×27+19×25
31×870+13×310
4×(25×65+25×28)

①8100÷4÷75=8100÷(4×75)=8100÷300=27②75×27+19×25=(25×3)×27+19×25=25×(3×27)+19×25=25×81+19×25=25×(81+19)=2500③31×870+13×310=31×(10×87)+13×310=310×87+13×310=310×(87+1...