[3/4-7/8/(5/6+4/5)]*28
=[3/4-7/8÷49/30]*28
=[3/4-15/28]*28
=3/4*28-15/28*28
=21-15
=6
(1.25*4/5-0.76)/(1又3/8+1又1/40）
=(1-0.76)/2.4
=0.24/2.4
=0.1
[(0.2+1/3)*4.5]/(8又1/20-6.45）
=8/15*4.5/1.6
=2.4/1.6
=1.5
x+3又2/3=5
x*9又3/4=7又1/11 x/2/5=10
6又2/3-x=4.25 6.4*1.7+6又2/5*8.3
（4又6/7+1.75）/1又11/14+3又5/6
2.16-7x=0.06
1/2x-0.5=5又1/2
8.16-1.26/0.3*1.5
=8.16-4.2*1.5
=8.16-6.3
=1.86
8.4*[(1.2+3又1/3）/3.4-1/2]
=8.4*[68/16/3.4-1/2]
=8.4*[5/4-1/2]
=8.4*3/4
=6.3
5.8：x=3又1/2:7
3.5x=7*5.8
x=7/3.5*5.8
x=2*5.8
x=11.6
3/10*55-4x=14.5
16.5-4x=14.5
4x=2
x=0.2
19.38-4又7/8-5又1/8
=1.938-(4又7/8+5又1/8）
=19.38-10
=9.38
13又7/13-（6又3/5+3又7/13）
=13又7/13-3又7/13-6又3/5
=10-6又3/5
=3.4
1又3/4+[2又3/14-（2又3/14-1.875）]/2又1/12
=1又3/4-15/8*12/25
=1又3/4-9/10
=0.85
（9.4-8又2/5）/[（1.1+1/15）*1又7/18]
=1/[7/6*25/18]
=1÷175/108
=108/175 先这么多吧,
