Question

计算下面各题.3.5/1又1/3+8.5*[12*(1/3--0.3)--0.15],3/2[2/3(1/4X+1)+2]

计算下面各题.3.5/1又1/3+8.5*[12*(1/3--0.3)--0.15],3/2[2/3(1/4X+1)+2]--2又1/2=2/3X、［5--(1又5/6+1又11/18)］/(4+4又1/2*6/7/9/14)、1/3+1/15+135+……1997*1999分之1

Answer 1

计算下面各题.
3.5/1又1/3+8.5*[12*(1/3-0.3)-0.15]
=3.5×3/4+8.5*[12*1/3-12*0.3-0.15]
=2.625+8.5*[4-3.6-0.15]
=2.625+8.5*0.25
=2.625+2.125
=4.75

3/2[2/3(1/4X+1)+2]--2又1/2=2/3X
1/4x+1+3-2又1/2=2/3x
2/3x-1/4x=1.5
5/12x=1.5
x=3.6

［5-(1又5/6+1又11/18)］/(4+4又1/2*6/7/9/14)
=[5-3又4/9]/(4+27/7*14/9]
=14/9/(4+6)
=14/9/10
=7/45

1/3+1/15+1/35+……1997*1999分之1
=1/2*(1-1/3+1/3-1/5+1/5-1/7+……+1/1997-1/1999）
=1/2*（1-1/1999）
=1/2*1998/1999
=999/1999