1. 3-(1.6-1 14/15)*6/7:1 11/21
1) 1,6-1 14/15=1 6/10-1 14/15=1 3/5-1 14/15=8/5-29/15=(8*3-29)/15=-5/15=-1/3
2) -1/3*6/7=-1*6/3*7=-1*2/1*7=-2/7
3) -2/7:1 11/21=-2/7:32/21=-2*21/7*32=-1*3/1*16=-3/16
4) 3- (-3/16)=3 3/16
2. 1 1/9(3х-9)-2 1/3(х-1,8)=10/9(3х-9)-7/3(х-9/5)=
=10х/3-10-7х/3+21/5=3х/3-10+4 1/5=х-5 4/5=0,75-5 4/5=
=75/100-29/5=(75-29*20)/100=(75-580)/100=-505/100=-5,05
3. 2:(3х/8)=1 4/9:4 1/3
3х/8*13/9=2*13/3
13х/24=26/3
х=26/3:13/24
х=26*24/3*13
х=2*8/1*1
х=16