2.7+3у=9(у-2)
2.7+3у=9у-18
3у-9у=-18-2.7
-6у=-20.7
у=-20.7/-6
у=3.45
0.3(8-3у)=3.2-0.8(у-7)
2.4-0.9у=3.2-0.8у+5.6
-0.9у+0.8у=8.8-2.4
-0.1у=6.4
у=6.4/-0.1
у=-64
5/6(1/3х-1/5)=3х+3 1/3
5/18х-5/30=3х+10/3
5/18х-3х=10/3+5/30
-49/18х=105/30
х=105/30:(-49/18)
х=-1 2/7