( 2.8 + 3.85 ÷ 3.5 )
4个回答

1.原式=[2.8+(3.5+0.35)÷3.5]x4.6

=(2.8+1+0.1)x4.6

=3.9x4.6

=(4-0.1)x4.6

=18.4-0.46

=17.94

2.原式=(10/15-6/15)÷(3/24+10/24)

=(4/15)÷(13/24)

=32/65

3.原式=30÷[(1/4)x(7/20)+(2/7)x(7/20)]

=30÷(7/80+1/10)

=30÷(7/80+8/80)

=30÷(15/80)

=30÷(3/16)

=160