1.
3/4(4/3х-4)-8(2 1/4х+3/8)=3/4*4/3х-3/4*4-8*2 1/4х-8*3/8=х-3-8*9/4х-3=х-6-18=х-24
2.
2/9(1,8m-5,4)-3/7(2,1m-4,2)=2/9*18/10m-2/9*54/10-3/7*21/10m-3/7*(-42/10)=
=2/5m-6/5-3/5m+9/5=-1/5m+3/5=3/5-1/5m
3.
1/3(0,3у-0,6)-1/4(0,4у-0,8)=1/3*3/10у-1/3*6/10-1/4*4/10у-1/4*(-8/10)=
=1/10у-1/5-1/10у+1/5=0