3: A
4: C
三
1: 24 10 0.5 2/3
0.027 3又3/5 27/8 20
2: 1050÷7-24x4 10.5-6.25-3.75+7.5
=150-96 =(10.5+7.5)-(6.25+3.75)
=54 =18-10
=8
3/8x30+2÷8/3 56x(1+4/7)÷8/11
=3/8x30+2x3/8 =56×11/8x(1+4/7)
=3/8x(30+2) =77x(1+4/7)
=3/8×32 =77x1+77x4/7
=12 =77+44
=121
5/8÷[13/12-(1/12+1/4)]
=5/8÷[13/12-1/12-1/4]
=5/8x4/3
=5/6
(1/8+1/4-1/6)x24
=1/8x24+1/4x24-1/6x24
=3+6-4
=5
3: 5/9:x=2/3:36 5x+12.9=37.9
2/3x=20。担?剑玻