1、(28+2)÷(1-1/8×2)
=30÷(1-1/4)
=30÷3/4
=40(kg)
2、160×2/5+20-6
=64+20-6
=78(吨)
3、30÷(1-3/5)÷(1-4/7)
=30÷2/5÷3/7
=75÷3/7
=175(个)
1、(28+2)÷(1-1/8×2)
=30÷(1-1/4)
=30÷3/4
=40(kg)
2、160×2/5+20-6
=64+20-6
=78(吨)
3、30÷(1-3/5)÷(1-4/7)
=30÷2/5÷3/7
=75÷3/7
=175(个)